How to Align Graphic with heat press?

Use a Tee-SquareIt tool or aLogo It tool. They are available at some of the preferred vendors on the left or you can google it.

I looked into to that but I was wondering if those are the only ways or is there a make shift way to do it at home, without folding down the middle that is both fast and accurate.

The TeeSquareIt tool works great, but as you move to bigger size shirts the placement of your graphic will change, what looks good/centered on a LG shirt won't work on a 2X, it'll be too high on the shirt (of course this depend on the size of your graphic), really trial, error, and eyeballing it works just as good once you've done a few hundred shirts.

JMHO