Fruit leathers - my favourite is banana and strawberry...
Blend 2 'nannas and a tin of strawberries (or similar amount of fresh in season fresh) and spread them about 3mm thick on the non stick sheets.
When dry and leathery dust with icing sugar, roll up and slice into 1/2" pieces.
Jerky - invent a marinade to your taste (soy sauce, Worcester Sauce, garlic paste, ginger powder, black pepper, tomato paste is one of my favourites), slice skirt beef into thin pieces/slices marinade overnight then dry until like leather. Resist eating it all in one go.
Veggies - almost any work - slice thinly and dry until bone dry. Celery is great dried and then powdered and then used either as a condiment or added to soups etc. Drying celery will amaze you as it consists of almost nothing but water and you get very little bulk but a lot of flavour when you dry it.
Fruit - Pineapple is on of my favourites - slice into 1/4" rounds dry until it is like a toffee. Delicious.
Strawberries - unbelievable flavour! Slice big ones into 2-3mm pieces.
Tomatos - slice cherry toms in half and dry cut side up.
That should start you off