•Copies your passport. Do you have a passport? Then make several copies, this step is used to overcome bad condition at future. This is so important, so if you haven’t made copies for your passport, make it now.
•Bring cell phone
Do not forget to bring your cell phone, at least 2 cell phones if you can. Bring your cheaper cell phone anywhere and everywhere you go out, the other one (expensive) keep it in your backpack/bag, under bedroom, or somewhere else that you think it is safe. And don't forget your cell phones must be able with GPS system. I know it sounds like espionage mission, but it is for your safety.
Do not go out until morning, especially if you are a girl or woman. And respect local culture that concerning decency issues.
It is important to know the lay of the land before you arrive. That means doing research, reading maps and guide books and talking to certified travel professionals who have experienced the destination first hand. Know where your hotels are located, how you will get around and where you want to go. The fewer decisions you need to make when you first arrive, the less likely it is you will get lost or distracted.
•Research your hotel
Not all hotel rating systems are equal. Some do not include a full inspection, others are based on traveler reviews, which are not reliable, and others do not take into consideration hotel service and only look at the hotels’ physical features.
•Avoid single supplement fees by using a travel professional
Many tour companies and cruise lines charge extra fees for single people who travel alone. Bring this matter to expert travel counselor that can help you find deals for single travelers that are not available or may be difficult to find on the Internet. A travel professional can also assist solo travelers by placing them on the vacation product (cruise or tour) that best suits their respective lifestyle needs with like-minded travelers.
It is nice if you could melt with local, but remember you are tourist. You can trust with strangers at outside, but do not trust them at inside. This is so important if you are girl/woman. Other thing is, do not accept drink from someone at bar/cafe/restaurant if you never order it.
•Always use padlock that has security number
It's not too effective, but at least this way can reduce your chance from losing or someone put something (drugs) into your bag.
•Always check your backpack/bag
Before you back to your home town, always check your backpack/bag. This is to avoid you from drug smuggling, especially if you invited someone to your room at night. You are not interested to get permanent vacation in prison, aren't you? Or maybe death penaltythat is applied in some countries, such like; China, Malaysia, Indonesia (if possible), Singapore, etc. Besides that, this act also to prevent you from losing your stuffs.
•Always calm and confident
Try to always calm and confident, if you don't. Others will pick up on your cues and sometimes just acting confident will do the trick.
•Secure your credit card number
Take along the emergency numbers of the credit card company and card number information (keep in separate secure area on your person) if you should lose your wallet.
All steps at above are just my opinion when you traveling alone, you don't need to be paranoid, just beware.