Link exchanges used to do a lot. These days not so much. You can still get a benefit from them, but you need to be careful. Don't use the same anchor text, try not to get sitewide footer links, and only do so with highly valuable partners.

I mean if you can get a DA 90 site to link back to your DA 13 site then yea a link exchange would probably benefit you a bit.

But overall 1 way links are the best way to go.