How to Comment on Blogs Without Spamming for SEO

Blogs, forums and other such elements of websites provide us with a great way to generate a community for people interested in a certain topic. Blog owners often get to know each other and help promote each others' sites, forums generate their own content and encourage repeated visits, and even help networking. From an SEO point of view this has many advantages, but not only for the owners of the site, but also for the visitors who can use this as a way to network, as a platform for reaching interested parties, and as a way to of course get your link on a site that ranks well with Google already. You can write whatever you want in a comment on Blogger or Wordpress so it's easy to drop your link into your comment and improve your SEO.
However this creates an alluring temptation for many people to place as many links as they can on peoples blogs by posting hundreds of comments on blogs that they know nothing about. This is incredibly frustrating for visitors and blog owners as it's tantamount to spamming. This can potentially get you banned by Google, but more to the point it will put people off visiting your site as you look interesting and intelligent so the assumption is that your site will be too. More importantly though, comments that look like spam are far more likely to get deleted. Thus if you spend the same amount of time posting just a few well written posts as you would posting hundreds of comments on hundreds of blogs, you will probably end up with more links remaining in a month's time - and those posts will be less annoying for everyone else as an added bonus.
Going about posting a comment with a link that's not spam takes a little bit of time and thought. First of all: read the post you're about to comment on. If you do not then you won't know what you're commenting about, as in your comment you should respond to or elaborate upon the point made in the blog post - probably using your link. This also means that you should only comment on relevant blogs, which is something that Google will reward you for as well. When you comment too, make sure that you respond to the comments that are already there too or you will look like a robot, posting without making any 'conversation' or observing the unwritten rules of internet communication.
There are other ways to make yourself look more authentic. One is that you should have your own blog and your profile with Blogger, Wordpress or something similar. If you do then people will be able to follow it to find out more about you, and to see that you genuinely are interested in the topic. Bloggers love networking with other bloggers so this is a sure way to be 'in' with the crowd. Finally, having your own profile will give you yet another place to put your link which many visitors will find.