The SEO methods You use

So I started a website a few months ago, I really enjoy making posts for it, I'm monetizing it using adsense, I have been doing all of its SEO manually, and I was wondering is there anything other than comment backlinks that'll help my website? I still have pr0 my website is awesomesciencestuff.com if you could check it out and tell me what you think, and share you backlinking methods, I would love it if it's manual, I don't have the money to buy the software

Well you can start getting backlinks from social bookmarking sites, creating a facebook page and increasing your social media (twitter,google+,facebook etc.) presence will add value to your site. Social signals are playing an important role in today's seo, so use them if you want to get long term ranking. These all can be done manually.

You can create free web 2.0 on various sites like blogger.com,wordpress.com,squidoo,tumblr etc. Keeping your web 2.0 updated will be helpful for your site. Creating pinterest account can also be useful. So all these can be done manually.

btw I shared a list of 400+ sites yesterday you can use it from:
http://www.blackhatworld.com/blackh...ng-includes-80-google-page-ranking-4-6-a.html

start social links. Make a fb profile and start sharing your content there. Post status updates with relevant keywords, start liking other peoples pages. If you still have the time get some web 2.0 backlinks.
Good luck