You can make your own graph paper using a spreadsheet program. Something that's 2x2 or 3x3 lighter lines inside a 1cm x 1cm heavy lined square. In addition to that, I think the RevTK review cards have a "grid line" option to further help.

In reality, I'd say don't overly worry about this. Unless you're learning Shokudou, you're not going to be drawing characters outside of reviews. The reason you're writing is it's the best way to create the muscle memory in addition to offering solid proof you were thinking about the correct kanji. Nice looking kanjis are a nice to have but not a need to have.