How to do private drawings / notes on map and viewable tokens

Is there an easy way to keep drawings and notes privates on maps and viewable tokens? For example, the game I am moving into roll20 has a map that a player might want to draw private strategy on but not share. Tokens are locations that whomever visits them can put resources there... but we do not want another player seeing those resources. Just checking how much of the game I can move into roll20 and how much needs to stay on pen and paper.

There is no means for a player to draw anything privately, outside of the GM moving that player to their own page ( Split the Party ) and not moving other players to that same page. The GM can draw things privately by going to a different page from the players, or by drawing on the GM layer. Players can write in the bio or notes fields of any Character or Handout they have edit privileges for, and they cannot view any Characters or Handouts which the GM has not placed in their journal. The GM could therefore create a Handout for each player that only they can see to use for private notes. The GM has access to a GM Notes section in both Characters and Handouts that only the GM can see or edit. The only thing a player is capable of keeping from the GM is the content of whispers.