I guess tech analysis knowledge and risk management. Also good software.

Personally I trade on Bitmex (futures) with trailing stops (highly recommended) and support my trades with Bitinsure app. (https://www.bitinsure.com/)
It controls my risks (drawdown, losses and other trading limits and sends me alerts when any of them is reached. Also it gathers and calculates real-time stats so I do not spend any time on monitoring my accounts, looking of drawdown and other risks and have my performance stats at hand