This pretty much depends on the coin tbh. In the beginning, I grabbed some fast profits and re-spread the profit on other coins. Mostly seed investments.
I think the bag I have right now is 90% the same since 2-3weeks and I haven't changed much. Maybe some small profit sales and re-invested in other existing coins in the bag in order to have a more healthy weighting.

Ah not true, yesterday I finally decided to kick-out my LTC bag (bought for 3BTC, sold for 2BTC) and bought some new coins too, for 0.5BTC each.

I plan to keep the existing bag like this until the end of the year as I am extremely happy with it's setup and future outlook. As I am quite heavy on DGB, I might cash out a little on 8th or 9th of June, depending on the price reception of minecraft private server and citi startup contents. These profits I would put in 2-4 coins I consider missing in my bag, but hey, you can't catch all the pokemon...