Got a bare fence ? perhaps behind a narrow border or lawn.....
no.1 : Try growing raspberries if you've never done so before. Best to put a framework of wire on the fence. I use 3 strands. Raspberry canes are cheaply bought or if you know someone growing them already you can get offshoots from them for free. Don't plant them too close to the base of the fence and you'll have something very beneficial to bees and then get a crop for yourself or the birds.
no. 2 : For supporting climbers and to create an additional wildlife habitat...put up 2" square plastic mesh so that if sits about 4" away from the fence. I use long vine-eyes in the posts and in the middle of the panels (depending on the type of panel) I put small wooden platforms. This helps support the mesh and when your ivy etc are established, gives birds are starting point for nesting. Wrens and titsespecially like foraging in the gap between the fence panel and the mesh 'screen',