Always smile be polite... gets you a long way.
Drink water even if you dont think your thirsty, dehydration creeps up on you.
Wear deet with pride dont want that dengue from the rarer daytime aedes egypti mosquito.
Try to barter and haggle for good prices on market stalls.
Do your research on scams especially bangkok and pattaya.
Stay away from drugs
When bartering on motorbike rental price haggle on 1 day even if you want it for 3 days get good price then ask how much for 3 days and so on.
Take electrolytes and activated charcoal capsules and acidophillus probiotic capsules.good for preventing diarhorrea ,drawing out toxins from eating the wrong thing and help digest food better. Electrolytes give the body much needed replenishment when dehydrated.
Wear sensible respectful clothes when entering temples.
With motorbikes front use front brake when turning is a great tip too.
Use a secure wallet/money belt
Theres a lot more i can tell you so feel free to ask.
Use travel card or credit card at atm to reduce charges as well as take what cash you can.