For my first real woodworking project I'm making a desk for my day work. I've roughly cut - with tenon saw and mitre box - the legs to more than the required length, as it's hard to store 4m lengths in my house.
I notice my rough cuts are a bit angled, which explains how I destroyed my mitre box. Now I want to make fine cuts so that the legs fit into the apron, how can I ensure my cuts are straight?