What is the best way to improve Crazyhouse or Bughouse skills? I have been playing Chess variants for a while now, and I would like to know how to improve my skills in bughouse and crazyhouse. Does anyone have any tips or strategies that would apply to either? Any input would be very helpful.
Since there isn't much material out there to study, the best way is to play with better players.  Of course, studying tactic problems is great for chess and the variants. FICS (free internet chess server) is probably where the best Siamese (bughouse) players are.

It helps if you have some opening systems worked out (since in Siamese being ahead on the clock can be crucial).
Published tips are here: http://www.freechess.org/Help/HelpFiles/bughouse_strat.html
https://www.chess.com/blog/Sorsi/advanced-bughouse-tips