When I can't finish an album : don't try to finish it, but only put previews / promo extracts on the net.

Also: for the tracks I can't finish, put online the track as it is with fade in (and / or fade out) to make it look like a simple extract.

Composing an entire demo in less than a week. Forgetting what you've composed, rediscovering it weeks later, with admiration, and the impression of hearing what someone else has done.

General MIDI files forgotten on a floppy disk.

(that we rediscover years later)