I have made some picture frames. Without fancy wood working tools, it requires a Good framing clamp. Key is the word "Good". Trying to line up, glue and tighten 4 individual pieces of wood together without having them pop out on the corner can be very challenging. Luckily, I was going for the rustic look with old barn board so imperfect joins added to the look rather than detracted.
Of course, that was before I owned a router and now a lot of better jointing methods are available to me to help solve that problem.
Here is a good page of pictures of joining methods from a quick google that will help..
Wood Joining Pics.
