Here is a supply/demand zone drawn out for bitcoin on the daily chart.
Typically, the best way to trade demand supply/zones is place a few long/short orders just above the demand zone, and just below the supply zone. Making sure the level is fresh (hasn't been penetrated before) will also drastically increase your odds of success.
You can see that on the bottom demand zone, bitcoin didn't penetrate, so that demand zone is still FRESH, meaning that if it ever revisit, chances are it will pump back up again.
The middle supply zone at the top is not so fresh, meaning that a strong move CAN break up from that zone. We have already had 2 retests, the more retests, the higher probability of breakthrough.
The topmost supply zone is fresh, meaning that resistance there is strong.
PROTIP: Rally/Dump after hitting supply/demand zone needs to be 3 times the size of that zone to confirm that it is indeed a supply/demand zone.