From the title, one may thought that I will tell some tricky or black hat SEO works to apply on your web site, but I am not. I will discuss about getting Search Engine Ranking without doing any SEO job you may know come under SEO.
1st is content. It is obvious that if you have good content (or good service, if your site is ecommerce site) then you will get good traffic even if your SEO is not good. What will happen is that a searcher will find you after lot of searching. He got that your work is very good, so for not forgetting it, he may bookmark it for visiting here again. He may bookmark it in social bookmarking site as well. If he bookmark it on social bookmarking site then your site will be exposed to many other similar visitors. and he can again do the same. So, good content or service can give you automatic advertisement.
2nd can be Site design and navigability. Yes, good web design can give good first impression and your first time visitor will be tempted to browser more after good impression. Good navigation and ease of browsing will help web site visitor find the content he is looking for and he will feel satisfied. If you sell a product from your web site then this is directly translate in money.
3rd can be web site speed or loading time/response time. If you web site is too slow then your visitors will feel that they are not on a good site or it is buggy. So, she may drive away to searching new site for the content or service she was looking for or will click on the next search result on search engine result page. So, web site performance is very important.
4th can be engagement with your visitors. if you visitors commented on your blog and you can quickly approve it then any visitors can feel good about the response he got. and if you approve it like me (takes many hrs) then many visitors may not like to comment next time. Similarly with placed order through web site. Here it is very important than you can send email about the confirmation and other expected details to users as quickly as possible. So that users can read the email just after placing the order on his laptop and he do not need to come again to laptop and check his details.
5th can be community. Your community may matter in this neck breaking competition. Community on Facebook fan page or through mybloglog.com, what does matter most that you have a responsive community that is following you and indirectly advertising for you. community is attached through emotion so getting first hand quality feedback and based on that correcting your mistakes is easier. This may ready you for taking first time visitors/customers. Communities can be build through culture, hobby or geographic area wise.
Site navigation again. Heading is a very useful part in site navigation. Google suggest using the natural headings to help visitors search site better and not for search engine. Like you should use h1 tag for top most content and not after h2 tag or your Post heading. In your blog, your post is most important part. or you can also say that my Web site name is most important. Then your web site name or post heading can be h1 tag. If some want to give h1 to any search term and they could not find find good keyword according to him in headings then he will make any text inside post content a h1 tag and apply CSS for making equal to other text inside post content. This is against general principle of site navigabibility. H1 tag is the biggest as this is for top most heading.
H1 to H6 Headings size: