Provide High Value Content

That’s the basic element to increase traffic. If you don’t provide value on your site, visitors may come, but never return. And they will tell 10 others.
The more value you offer to your visitors, the more visitors you will gain over time as they will tell 1 or 2 friends about you.

This already implies that this strategy will NOT increase traffic overnight. This one is a long term process. On the positive side great value will definitely put you in good position for the long run.

Check if backlinks have a “nofollow” attribute

Link exchanges are still one of the white hat ways to build backlinks but unfortunately, there are many unscrupulous webmasters, who will cheat you. One of the scams is when you pay somebody for a backlink, it suddenly disappears or has the “nofollow” attribute. That is why you should check from time to time if the link is still there and if it doesn't have the “nofollow” attribute.