At the end of the Day this is a very trader specific questions. Trading with a moving average system is dependent on the traders preference. If you do not understand the best way you personally should be trading, you are likely setting yourself up for failure from the beginning. I recommend you read "Trading for a Living" Dr. Van K Tharpe
There are hundreds of books written on trading with moving averages. There is no rule that works 100% of the time. 10 and 21 is traditionally used by institutions, but that does not mean you can't be successful with a 20 or 30.
You need to play with a moving average combination that works for you, and your personal trading style. I highly recommend paper trading you strategy before trading live with actual Bitcoin.
The biggest thing you need to figure out, is what type of trader you are, and the frequency of trades you want to be taking. If you are a day trader the 1 and 15 min may be what you need. If you are looking for a trade maybe once a week, the 5 and 10 might work. If you are looking to take trades over the course of weeks, 10 and 20 on daily chart. If you want a few trades a year 50 and 150 daily. Trading all of these time frames, could be over whelming, and just result in losses.
Any moving average combination can be used by any trader provided
1.) They are disciplined in the strategy
2.) Have back tested the strategy
3.) Have appropriate risk management
If you can not explain to someone exactly how your strategy approaches all three of the above points, you need to stop focusing on the moving average pair you are trading, and reevaluate what your trading strategy is.