A rotary cutter is a must have if you cut a lot of straight lines, and once you have mastered the art, you can do curves with them as well!
You can get ones with smaller blades - which I do also own, and maybe better with little curves. I have to admit as I don't do much intricate work have rarely used it.
I have one that will retract when not in use, and saves any accidents, I just can't imagine cutting with scissors now.
Get a cutting mat, the largest you can accommodate they are not that expensive. Mine has inches on one side and centimetres on the other side it is 23" x 17".
Fed up with facebook etc and want a crafty natter would be lovely to get the forum up and running again, follow the link at the top of the page.