Holding them or trading them with altcoins on trading sites like ecoin.eu. I trade my btc for LTC and wait for it to rise up but its quite bad for LTC nowadays.
Two years ago, I got some hefty profits by converting my BTC to LTC, but I'll not recommend it to anyone. In January 2013, the exchange rate was going at 1
BTC = 400 LTC. I converted one of my coins to LTC. Then a few months later, the exchange rate climbed to 1
BTC = 40 LTC. I got almost 10x profit, but lost most of it later in an investment scam.
If you gain 10 times of your investment that is called good investing.
But if you lose then all then that is a bad thing to do.