Disclaimer --- These are not guaranteed and you will need to assess the situation for yourself before undertaking. Some are just good advice in general.
1. Know / Be Aware of Your Surroundings. Attackers and thieves look for easy targets. Those who are not paying attention or who seem unaware of those around them. In this way criminals can work on the element of surprise, do their crime in a flash with less fear of being caught. So see who is around you. See if you are being watched or followed. Keep your eyes open and attention sharp.
2. Avoid getting into a very crowded group or, if a group crowds around you, be suspicious and protect your valuables. I can't tell you how many times I have been on a bus, when a group of young men suddenly crowd around me. The rest of the bus was empty but I was surrounded. They were trying to pick my pocket! If this happens, do the following....
3. Make a noise! If you are being attacked or pushed, prodded or otherwise molested, yell out and don't be shy! "Police!" is a universal term. Thieves want it quiet. So make a racket.
4. If you must carry your valuables do it in a money belt. Do not carry anything valuable in a handbag or other carrying bag. There are some good ones that simply slip onto your belt loop so they are easy to whip out to get extra cash etc.
5. I try to carry pepper spray but when I can't (like traveling by plane) I carry bug spray or hairspray aerosol to use instead. Fighting back is something you have to ascertain for yourself. You might find that spraying something into the attackers' eyes can stun them temporaily and give you a chance to run away.
6. I also carry an easy-to-reach sharpened pencil. Little hands trying to reach into your pocket can get a pencil point in them. Ouch.
7. Obviously, don't walk down dark alleys alone, if you can help it. In India, even women who are walking with a man can be attacked. The criminals who roam in packs attack the man and disable them and then attack the woman. Know where you are going.
8. In a bar or restaurant, don't leave your drink unattended. If you have to use the bathroom either take your drink with you or order a fresh one (and watch them make it) when you return.
9. When checking into a hotel, don't let the clerk announce your room number so others can hear. Have them write it on a piece of paper and hand it to you. Others could be lurking and could then know where you are staying.
10. When staying in a hotel room, check all windows to see if they lock and be sure that the door locks and if there are any other doors (like to join adjacent rooms) to be sure that they lock. Also check closets and under the bed. Should anything feel amiss, ask for a new room and do the same check all over again. Also try to stay on middle to upper floors and not have a room next to another roof. You get the idea...