Those are the most common ways of earning bitcoin, if you don't have enough to invest perhaps you can save up so that you may buy some bitcoins.

But aside from that, yes, offering other types of services is a way for you to earn some bitcoin such as graphic design or programming. I think there are a lot of people here looking to hire for those who have the skill, you could also join signature design contests. A lot can be see in the marketplace section of this forum. There are also other websites that hire freelancers with various services which offer to pay for bitcoins.

These things consume a lot of work and time to earn small amounts because it is not an easy task to rank up your blog. If got that talent then try with google Adsense program because at least they will pay a higher amount per click compared to other pay per click programs. Later you can convert your earnings to Bitcoin once you receive your payment from Adsense.

If you don't want invest money as a beginner and also want to make earnings then obviously you needed to do some hard work and needed to spend time .
You can choose survey sites and also faucet sites where you can make free Satoshi per hour like at freebitco.in .
So overall you need to work for very small penny amount of money and i think that is totally wastage of time for you because you will get 100 Satoshi maximum per hour in the faucet , so totally lost of time and time = money .
Here my suggestion for you to make analysis about the trading because you can get success with the trading only , you just needed to make earnings of small amount of bitcoin and then start trading , but trading needed better experience to handle thr down and up in the price of the coin , so it will be more better for you to understand the trading and in this way you will get better knowledge about the bitcoin and bitcoin trading and you can untilise this knowledge for your future progress in bitcoin field .

Actually, there are lot of ways to earn bitcoin. Trading and joining in campaign is the best sources of bitcoin. You can also earn bitcoin in faucet and mining but it takes time to wait. You can't gain much income if you didn't invest im bitcoin. Lastly, you should invest in some trading or investment sites if you really want to gain more bitcoin.

if you dont want to invest but you need to earn..i recomend you to offer your skills or take a faucet task..or  joinon signature campaign her in furom..

Join the bounty on some ICOs is also good for beginner to earn bitcoins. You also can do surveys, reviews and make an article about some ICOs or something and post it on your website/blog, all these are free and almost all people can do this. Or you can try your luck by buy some dead altcoin and hoping the price will increase in the future, not recommend this lol.

There are still other ways like offering your service, or selling items for Bitcoin, build your reputation and become campaign manger or loaning btc, looking for airdrop or giveaways, there are no limitation on earning through BTC, you just need to look for opportunity and be creative