Ha, I like the period change one - I'd never thought of that.
Unfortunately, these won't work once you get to college or, for that matter, any class where they give you set requirements on the margins and font type and size.
The best way is to write an intro that is at least (now this is on a five page paper - it shouldn't be as long if the paper is shorter) half or three quarters of a page long... get really creative. The conclusion should be the same length... for everything in-between, provide multitudes of examples, i.e., like the time when I had to write a psych paper on dream interpretation, and listed different types of dreams that people have, and when I was comparing and contrasting Freudian views with the activation synthesis theory, I talked about dreams that could not possibly have occurred as a result of activation synthesis, and described them in great detail.
See? =) The trick should be in the writing, not in spacing and such. It's an acquired talent. You have to make sure that it's not too ramble-y... it works quite well, actually, and will do wonders for your papers if you learn how to do it right =)
And if you're absolutely stuck, make sure you put two spaces between each sentence, rather than one...