Is link exchange a good SEO practice? If yes, where to find link exchange partners?
Forum links are not effective now as it seems. Where to find the pages or sites to get links from?
I suggest you read Google's guidelines on link schemes and put your energies into something more useful.
If you're a bear made of mohair, ponder on the nature of a mo.
Link exchange practice is okay. But there are several disadvantages involved such as: the website that wishes to exchange link is new and it has no PR or Alexa rank yet; the website has a lot of outbound links; it is also not okay to exchange link with a site that is not related to your niche. It is good to exchange link with a site that has a lot of traffic, provides quality information to its visitors and of course, it should not compete with your website too.
Still a good practice to increase seo visibility. You can approach your friends and even competitors in same niche.
Just ask politely. If it comes it comes, if it doesn't, then just move on.