When you are choosing the crypto exchange, look at and compare cryptocurrency platform fees, among other things. Using some crypto exchanges you will pay a percentage of each deal, using other ones you will pay for income and outcome transactions. You need to pick what fits you more. For example, Bitfinex charges Maker 0.1% and Taker 0.2% in fees based on the volume. Kraken charges Maker 0.16% and Taker 0.26%. European BitBay charges both types at 0.43%. You can see and compare fees schedules here.
For people who don't pay attention to development trends - one observation of high significance is Go popping up in the popularity list associated with Ethereum. Why is Go in particular an important sign? It's almost as fast and less clumsy compared to C++ and C Sharp. At the same time, it's relatively new. People who know Go are experienced and choosing to learn it because it is better. In my opinion, it will be the default backend language for most Silicon Valley tech companies in the next 5 years. Those same people are choosing to play around with Ethereum using Go.
At that point, you can begin trading. You can submit market or limit orders. The orders will be filled as soon as your buy/sell order can be matched to a corresponding one. Most exchanges only offer this limited structure for placing orders. However, a growing number of exchanges now allow more complex orders, including the option to go long/short on a stock and to employ leverage.
Don’t be greedy. No one ever lost money taking a profit. As a coin begins to grow, the greed inside us grows along with it. If a coin increases by 30%, why not consider taking profit? Even if goals are set to 40% or 50%, you should at least pull out some of the profit on the way up in case a coin doesn’t reach the goal. If you wait too long or try to get out at a higher point, you risk losing profit you already earned or even turning that profit into a loss. Get into the habit of taking profits and scouting for re-entry if you want to continue reaping potential profits.