There are 5 tricks i can give you . I have tried all of this and get better enhance , 3 times attempt all +21 , i haven’t pass +23 barrier yet .
1.Using many low level white , after +11 , the rate of success goes flatly 50:50 , after 2 fail on the white > 1 success each , after 21 however it won’t works .
2.One-shotting anvil . Goes with any charging multi-hit skill .
3.Channel surf , after each fail go to another channel .
4.Do it on maps that do not have maps , like bokor master house , pyromancer master house , highlander master house , fedimian mission office , etc . Or the empty spot , the less people the better .
5.1 day 1 enhance after passing safe enhance limit . This works until +11 . Be careful you need to actually logout before the server timer day change .
Better use them simultaneously , pray , and be prepare to get poor . hope this helps .
Believe it or not, up to you.