Well I do a lot of things alone, including some international travel, but then I'm pretty introverted and I like being by myself and left alone. As for tips, I would say be aware that most prices you see advertised for anything overnight are for double occupancy, expect to pay more. Know your standards and be assertive about them, you may get some rather rude and disrespectful propositions, but a firm no and looking at people like they rate right down there with pond scum will usually drive your average slimy guy away (at least for me it will, but I'm white, obese, and I've got the death glare down to a fine art).
I'm very planned out so I like to have all my stuff pre-booked and organized so I don't have to make those decisions while I'm traveling, but for the most part you don't need to book more than a day or two in advance.
I enjoy about half the vibe of staying in hostels and budget traveller places instead of hotels. It's cheaper, easy to book tours and activities, and it's an environment where people are looking to connect and chat with other travelers. If you look around a bit you can usually find private rooms or female only dorms. You tend to run into a lot of laid back and pretty worldly people, but usually there's a live and let live quality to it where people will invite you along but not be offended if you refuse. So "temptation" abounds, but if it's not really something that interests you there won't be a lot of pressure.
If you're going very far away, do your research on weather, how much money you might need, what payment forms are accepted, basic social and cultural things. There are even some websites for women traveling alone.
I haven't done a proper package tour alone, but I think I might consider it. But as seoul has pointed out before I wouldn't do one where I got stuck with a random roommate of uncertain values, I'd pay the extra for a single room. Nothing would ruin my vacation faster than a roommate who came back wasted and out of control or with a different guy to share her bed every night.