I've used a piece of paper and utilized the grid on the cuttingboard too, but for the most I've embraced the non-straight, off center, slightly out of kilter way of life, and I'm ok with it.
Edited by cshortel on 05-23-12 02:54 AM. Reason for edit: No reason given.
If I'm applying ribbon or setting paper or borders etc. I line things up on my cutting mat with the grid (has magnets too to hold things in place). However, if I'm doing letters, I usually just eyeball it and sometimes put them askew on purpose.....
Most of the time I can eyeball it but if my T-square ruler is close by I'll grab that. Especially if I'm trying to draw a straight line. It's very quick and easy.