I find it looks after itself.
Ive had it for 6 months and never done any tasks to keep it running well.
I install and delete apps on the go, ive got hundreds of sms messages on it, same with emails, I sometimes leave web pages open, got 20 GB's of music and hundreds of photo's.
Its still as smooth and fast as the day I bought it.
Its been turned off a couple of times because I had to save battery, but thats it.