UPDATE February.
NOTE. Any of these tips are based on my own experiences, you should always follow-up and use your own advice.
This will be my fourth trip to Mexico. Different considerations, because of a long and interrupted flight connection and because rules have changed. I’ll stay 4 weeks and need to be prepared. Let me say that in all of those visits I never met any Mexicans who were not friendly, accomodating and helpful. They definitely do not deserve a “wall”.
BAGGAGE
I will have three stops and long layover times at each, requiring hotels for overnight in Los Angeles. Meaning that any checked in suitcase will never arrive at my final destination. Decision, take one small carry-on suitcase and wear most of the clothing on my body. Coming from Canada is cold, arriving southern Pacific Huatulco is hot. Best, not to wear any winter clothes for the four hours it takes for me to get to Vancouver Airport. Instead, wear multiple layers of summer clothing and hoodies on my body. Pack only the most necessary items, like First aid Kit, couple summer tops, sun screen, and vitamins. [NOTE. All creams, liquids in plastic outside thru security check.] Leave space when arriving south to peel off your clothing and put into carry-on suitcase. Also, when traveling I always wear my special vest for wallet, passport, during trip toothbrush kit. The hotels will have everything I need.
MOBILE PHONE or CELL
I do not take mine this time, although it is unlocked. Reason: As per January 2018 there are new rules for immigration and customs controls. Like, customs agents can take possession of your phone, check data, download files or other stuff, for no reason whatsoever. Or, maybe just keep your phone. They now have the right without telling you why. Instead, if phone is needed the hotel may help. [NOTE. Easy to get SIM card on arrival Mexico City Airport, largest service provider in Mexico is Telcel. I usually buy call package only for international calls, if I take my phone. Check it out: [ http://extras.telcel.com/en/international-calling ].
Should have taken my mobile phone for at least emergency.
COMPUTER
Will take my iPad, camera kit and chargers. Hopefully get some decent network somewhere down there. Mexico is not exactly North America. Huatulco Marina Hotel Resort , no WiFi in my room, need do my business in the hotel lobby in the heat and noise.
FOREIGN CURRENCY
I am just going by my own experience in many travels, not browsing thru hundreds of travelers’ forums on this subject.
You can buy foreign currency in your bank account, then pick up at your branch (+/- 5 business days). Of course there is always gouging compared with the actual currency rates (C$ to Mex. Peso).
Example: RBC Canada has an online foreign exchange calculator site. These rates are the current 2018 rates for non-cash purchases. Buy cash foreign exchange thru your online bank account you will pay more for Pesos. It’s for the extra work to send and pickup the cash. When ordering Pesos at your Bank branch and you pick up you’ll get the rate as of that day of pickup. When buying Pesos at an ATM machine in Mexico, you may get better conversion rates. Problem is, how reliable are those machines ? Two things can happen: (1) The machine is physically out of cash, you get nothing except for charges to your Bank account. Therefore, always use ATM machines during the banking hours, not weekends. * (2) Your Bank can cancel your bank card (happened to me multiple times). Forced to use a credit card costs a bundle in those machines. So, best to buy expensive Pesos before leaving. US$ don’t help much, Mexicans prefer Pesos, and small bills. Nobody changes MXN 5,000 bill for you. *[NOTE. Machine out of cash, happened to me in Alberta, I was lucky I get my money back next business day from that Bank.]
UPDATE Huatulco Mex, RBC again cancelled my bank card, as they always do. Something wrong with their security programming.
WATER and FOOD
Careful, mostly not potable nor even suitable to brush teeth. Use bottled only or dilated juice or whatnot. Food: I like my veggies and fruits, only fruits I can peel. UPDATE. Hotels provide bottled water.
TRANSPORTATION, TAXI
I would never book any shuttle bus before trip start from a website. And be charged for it immediately. Because, most of these websites service airports and locations all over the planet. Don’t expect your pickup is there when you arrive after a lengthy flight way south in Mexico. Taxis, inside airport are double price than outside. Best get airport map ahead of time to know where you are when arriving. 2018 taxi maybe max. MXN 300 from HUX Huatulco to Santa Cruz resort area, if shared bus or more if private car.
UPDATE. Huatulco, Bus from airport to resorts only 140 Peso.
HOTEL
Never go by those beautiful elegant pictures they show you on a hotel’s website. Minimum, expect noisy air conditioning. Who knows it may be just wonderful. Never forget ear plugs.
Always be prepared, and GOOD LUCK.
LIFE's STORIES, ADVENTURES & TRAVELS 
Los Angeles Adventurer All Suite Hotel Inglewood
Los Angeles Adventurer Hotel – passing through
[ http://www.laadventurerhotel.com/ ]. Address: 4200 W Century Blvd, Inglewood, CA 90304.
In summary, this hotel is at best a backpackers inn, it is awful.
My recent experiences summarized. On my way down south to Mexico I needed to stay overnight in Los Angeles, CA. I had booked this hotel using http://www.booking.com. It is near LAX, L.A. Airport and advertised a number of included FREE services, such as BF, free Airport Shuttle to and from, free popcorn, free glass champagne on arrival, and whatnot. When entering the small messy lobby, there is a list on the wall listing all of these free included services and extras. These are included in the room price.
I have not seen any of this FREE stuff. I arrived late L.A., called shuttle service at this hotel from the airport outside an area which is reserved for shuttle buses from all L.A. hotels. We waited 40 minutes till a large black van arrived at the Airport, to pick me up.
This hotel is noisy, smelly (cannabis smoking), and the reception on my first arrival there was unacceptably rude with another guest, a Chinese man. Yelling and insulting this man, making nasty discriminatory comments on his being Chinese, and threatening to call the police. Just because he had requested another room. His room did not have a workable shower. Was scary this situation. In all my travels, this was a first for me.
I spent a few hours, getup early and got the hotel shuttle alright, to bring me to the airport. On my return back to Canada, I needed again to stay overnight at this same hotel.
Calling the hotel shuttle service from the airport, no response, a different company responded. I took a taxi to the hotel, cost US$25. The room I got was nice, I must say, with a nice clean renovated bathroom. The TV was on, the remote belonged to a different machine, no way to turn this off. So I pulled the plug to shut down this noise.
Got up early again, again no BF.
How they charge beats me. On arrival they take again a credit card for so called incidentals, although my cost for this room is already charged by booking.com on my MasterCard. The incidentals referred to apparently are a number of little bottles inside the rooms, sample liquor bottles, in case a guest actually uses them. I would not touch any of this with a pitch fork. On departure a guest will then be asked if they took any of this. Nobody does. Then the reception make out another receipt with another charge US$35, and on same receipt a refund of -US$35. Checked my MC account online, if in fact all of this has been charged correctly. Between the (incidentals) amount the night before and the refund the night after, there is a difference in US to C$ conversion. For many guests this seems beneficial to this hotel. Credit card charges are to Crown Airport Hotel Inglewood. Check it out: [ https://www.tripadvisor.ca/Hotel_Review-g32525-d77998-Reviews-Crown_Airport_Hotel-Inglewood_California.html ].