Most of the people uses bittrex and Plolniex. I use to trade on bittrex and bitfinex because I like them for being simple to use in so I go for them. In my case I prefer the transaction confirmation time more than the transaction fee where I use a local exchange. I have a very little investment as I don't have enough budget for trading but I follow a simple rule of buying at a low cost and selling at a higher. I am very keen with all the trading stuff because I can afford a little risk so I invest up to the level where I can bear it for a loss. Don't take much risk.