Quite frankly, if you’re not willing to carry a weapon that’s potentially lethal, you’re really not carrying a weapon that’s going to be much of a threat to an attacker. Further, that a weapon is potentially lethal, doesn’t mean it needs to be. Pepper spray is borderline worthless, regardless of how it’s used, mace is somewhat more effective, but even still, the effectiveness of either is going to vary from person to person. Some people are basically immune to them, and other people can have serious reactions to them. So, if you’re going to carry it, you’re going to have some potential of either altogether failing, or just being ineffective. So, frankly, if you’re going to carry a defensive weapon, it should be all about how effective it is in stopping your attacker; your first concern should be for yourself or whomever you’re protecting, not the safety of someone attacking you.
With all of that said, carrying a weapon isn’t for everyone. In general, though I am pro-gun and support people carrying, I do not own one or carry one for reasons that aren’t relevant to this thread. Instead, a little bit of knowledge and forethought goes a LONG way to protecting me and, of course, being in a generally safe area and being tall and obviously strong and in shape serves as a pretty large deterrent as well. So give thought to thinks like your situational awareness, appearance, location, escape routes, etc.
Situational awareness is by far the most important thing in protecting yourself, regardless of whether you carry a weapon or not. In fact, a weapon is pretty much useless if you aren’t aware of your surroundings and prepared to use it. If someone seems suspicious, keep an eye on them. Don’t walk around with your face buried in your phone, keep your eyes up and looking around. Know what kind of risk you are as a potential victim in a given situation and take actions to minimize those risks. And if you have an intuition that a person or a place might be unsafe, just avoid it. In every case where I’ve actually needed to defend myself in some way or another, I was never blind-sided, though in all but one I was able to defuse it before there was any violence, I was never caught off-guard, which is exactly why I was typically able to defuse the situation without violence.
With regard to your appearance, consider how you look as a potential victim. Avoid showing anything that’s particularly flashy in public unless necessary. If you are going to dress nicely, make a point of trying to stay in more public areas, with a group of people, etc. It’s similar with location, avoid areas that are generally known for being riskier, try to stay in well lit areas around people, places that are guarded, etc.