When you buy/sell via an exchange, try to use limit orders (try not to use market orders). On some exchanges, like GDAX, limit orders have lower fees than market orders. On GDAX, limit orders are free as long as they don’t fill immediately. Meanwhile, market orders result in a .3% fee, which is better than the 1.4% that Coinbase charges but not as good as 0%, especially if you are day trading. If your exchange rewards you for using certain order types, aim to use them.

Continually doing these things can lead one to gradually cultivate a strategy: a collection of signals that one is good at recognizing and that have a consistent track record. Some traders only buy or sell once they see confluence: multiple signals indicating the same oncoming reversal or trend continuation at the same time. For instance, they might look for candlestick patterns indicating a reversal on both a short-time-interval chart (like a 15-minute chart) and on a long-time-interval chart (like a 4-hour chart).

Now that you have identified the coins to invest in, you need to find an entry point for your investment.  Technical analysis has always been the best strategy for finding an entry point when investing in financial assets. The best way to use technical analysis in finding an entry point is to understand candle stick patterns. For instance, if you are looking to buy Bitcoin, then a bullish engulfing candle stick pattern on the weekly chart would be a good indicator that it is time to enter the market.
To stress some points made above, realize that a diverse portfolio and investment strategy will eat into gains as often as it staves off losses. The only way to make big profits most of the time is to make risky moves. If you go all in on a single coin at a given price and it goes up, that is a payday. If it goes down, your investable funds are locked into that crypto (unless you want to sell at a loss). Diverse strategies protect against this, but they will also eat into your potential gains (as it is rare for everything to go up or down at once). Know what you are looking for and know how to weight your portfolio to reflect that.
I have been using Coindex for a long time now and am constantly impressed by the time and care Josh and Cellaflora put into the project. There is an emphasis on perfection and testing the app's features before release and this has amounted to a polished and irreplaceable part of my iPhone. Coindex will always have a space on my dock and can't wait to see what they add next :)
No, the successful trader is not me. I’ve gotten lucky a few times and I’m still refining and trying out strategies; on the other hand, I’m part of communities of people who trade on a daily basis to grow their portfolios, and while some of the results can be attributed to luck, a majority of it is based on fundamentals, good habits, and experience.