Investing in incipient altcoins is part of my strategy too. But BTC leads the way to the other currencies. Take this crash for instance. Most alts have crashed deeper than bitcoin itself. BTC, Eth, LTC and such are the "safe" option, minor alts are very risky but by choosing the right ones you can literally get rich in a couple of weeks. However being too ambitious can lead you to lose all your money. So i think it is better to put more money in the ten big coins and then a smaller part in some interesting little alts. Anyway, doubling your investment in a year is not a marginal thing but an amazing feat to achieve.
That you describe in your first paragraph however sounds much easier that it really is. It is pretty, pretty, preeetty hard in fact. Nobody really knows what the market is going to do in the next minute. I avoid any form of short term speculation. It is the safest way to give your money to the proffesional traders that has a deeper knowledge of the market than you do or worse, to the whales trying to control it. Instead i try invest wisely and wait to see what happens.