For exchange trading, you can generally buy at a lower price and hold till the price is higher, but for margin trading, to hold too long maybe cost you a lot.
In order to avoid big loss and to make some profit every day, you have to follow the following rules:
#1 Limit the positions
Only one margin trading position any time.
#2 Follow the TA
Only open long when there is a bull, and only open short when there is a bear.
When there is a bull on a big frame, such as 1h, open and close a long position according to a small frame, such as 1 min.
When there is a bear on a big frame, such as 1h, open and close a short position according to a small frame, such as 1 min.