Question about recording midi track of no fixed length

Hey, folks,

Last night, I wanted to do a bit of an improv composition, using the new built-in synths. I didn't quite know how long I wanted it to be, so I ended up setting the sequence up for 256 bars, to give me as much as I needed, and then adjusted it down to the actual number of bars, when I finished. Was this the proper way to do that, or is there some other method for when you want the length of a track to be open-ended?

Thanks.