back when there was a spike i was mining litecoin for a few weeks but it wasnt very easy with crashes etc so i quit after a bit. i used about half of what i ordered on silk road and kept half and still have it. i got in to mining again in may, bought a lot of videocards and made some good gains, sold all the cards on ebay and just bought bitcoin with the money. i woulda been better off just buying the currency than mining in the first place but i came out close. mining was also creating a lot of heat and basically taking over my basement so im glad im done with it
right now you can turn a gtx1080 to mining with nicehash and if you leave it running 24h it will net you $2.20 US, after you pay for power thats a little less, but it helps to pay off your videocard. nicehash mines altcoins but pays you in bitcoin so you dont have to worry about exchanging etc but they do take a cut. also they only pay out every 0.01BTC so right now thats nearly a months of mining 24/7 on a gtx1080, and with difficulties going up constantly itll probably take 3 months. you can setup to just mine directly and then transfer on exchanges, usually pools pay out more often.
i dont plan on selling any btc unless it can significantly effect my life/ im hodling. also a little diversified with other altcoins but primarly btc