When making flags always be careful to not overdo the folds and details, or everything will get very messy. For the movement, when not sure always remember sine waves.
Other tutorials that might help you with the subject:
Manuel
2017-07-26 11:34:25 +0000 UTCGaz
2017-07-26 11:30:49 +0000 UTCJuniper Reiderdai
2017-07-25 13:20:50 +0000 UTCManuel
2017-07-25 13:02:30 +0000 UTC