The reality is that if you don't have access to the signup bonuses they give for US credit cards, you need to spend quite a bit to earn a useful amount of miles/points. So to me it looks like you won't really benefit from much of the programs discussed here.

However what you will also find here are a lot of people posting about great deals in airfare and hotels. Those will save you money immediately.

And what also might benefit you is that some of the airline programs are regularly selling miles you can use for award flights. Especially if you want to fly in the premium these can be a good deal. But you really need to read the T&C's and posts about those here first. And they do still require quite a spend.

If you rarely fly/travel I wouldn't bother. You need to invest quite some time and that's not going to be worth it.