What with Battlefield 1, COD, Titanfall 2 few others I ran out of space on my 512gb game SSD, never has it been known.
My Solution - download Steam Mover and lets me move a few of the games onto a partition on my 2tb hard drive and does all the dirty work for you. Simple as click click done and Steam Client is happy as larry.
Steam Mover
If I won't go back to a game, I just delete it. Internet is more than quick enough to re-download, plus no usage cap.
250GB OS SSD, 500GB Game SSD, 1TB Storage