Broad topic
Trader needs patience and knowledge about cryptocurrencies, that's the most important.
Another thing is to have right exchange, safety first. I can recommend Kraken or CoinDeal.
Trader need to remember not to invest more than he can afford to lose!
In my opinion, most important skill of trader which will actually help him in becoming successful far earlier than his fellow, is knowledge. If he understand his asset, digital market and this profession very well, nothing can stop him from becoming rich. After acquiring this weapon, he won't have to work on his patience and tolerance. They will develop naturally in him. he should never ever give up. In exchanges, Binance is also a good option.