Good links are ones that enhance the visitor's experience providing information that is complimentary to your site. For example a music venue will link to the web sites of the bands that are appearing. A site selling wild bird food may link to conservation organisations. A professional may link to his governing body so that visitors can verify his standing.
Give links on that basis without regard to return links. Solicit links where you think the rule would apply for the other site. If the links are one-way then fine, if they are two-way then that's fine too.