Haven't used earsketch, but here we go.
Answer:
1). Make a track in earsketch, make it like 6/7 seconds
2.) export your track as an .mp3, .wav, or .ogg (your choice!)
3.) (If on android) Navigate to settings, now search for an entry for ringtone.
4.) If you have no luck, look up how to set ringtone on your desired phone brand (iOS, Android, etc.)
5.) Test out your new ringtone
6.)Profit
