You won't get 1 BTC from it, but I've personally earned about 0.1 BTC with the following methods:

Faucets and PTC sites - Funded by ads, these sites will pay you a small amount of Bitcoins for either filling a captcha or visiting a website. There are many websites for this, you can find them by either checking out this website or by simply googling.
Casino giveaways - Many casinos give you about 1 mBTC (0.001 BTC) for registering at their website. Do not gamble these Bitcoins away, it's better to simply withdraw it directly. Sites providing giveaways can be found here.
Sell signature space - Once you have enough activity, you can sell your signature space and earn Bitcoins for every post made on this forum. Personally I'm using this service to do that (and it works good, I received 0.06 BTC for doing it last month), but there are many more if you search around a bit.
Earn Bitcoin from traffic - By using services like CoinURL or Coin-Ads you can earn Bitcoin when people click your links. There is also BitBin, which works like PasteBin but shares it's ad revenue with the users. There is also some ad providers in case you run a website, like A-Ads, BitAds, CoinURL and Operation Fabulous.
Earn Bitcoin by working - There are also people paying you to do different kinds of work. I haven't personally done this so I can't talk more about it.

Yes, and u can ask bitcoins for ur work, like designer, 3d, writer...etc

Mrgoldlake