Never advise someone to delegate their maximum SP mate. That will cause the user to lose all their bandwidth that they need to post, comment, and do anything with their Steemit account - including un-delegate their delegations.

You need to let people know that if they delegate 100% of their SP they'll lose access to their account. The only way to get it back would be to have another account either give them some Steem or delegate some Steem to them so that they have some bandwidth to burn.