When I plan to sell some of my hard earned BTC I never sell everything.

I think the best thing to do is always keep a mix of BTC, Alts and Fiat.

That said, to be successfull in trading you will have to do research before investing a part of your btc.

Personally I try to read many articles and when I have time attend to crypto meetups.

Also I recently some free software that predicts the future markets of several coins. www.cryptoforesight.org

Trading will always be an unpredictable job, but if you stick to it you will see the profit coming in.

Do your research and never give up trading as you will learn new things on a daily base.