Taking into account the overall length, any overlap and especially the curves can be a bit tricky. You may find that the first few times you bend and cut a piece of rebar it is shorter or longer than you had intended. This is often due to a failure to account for the length of the rebar through the curve. It can be tricky but you'll get the hang of it. Rebar is very easy to mark with wax crayon (if you'd like waterproof marking) or chalk (often handy in art projects where you'd like the marks to wipe off).