I have tried making homemade fries many times! My family loves fries but I don't often buy the frozen ones. I found a recipe and tips in a ParentsCanada magazine though that actually work! It is the tips that make the difference.
Tips: 1) use a dark baking sheet (it will conduct heat more evenly)
2) spread about 1 T of oil onto the baking sheet and put it into the ove. Then preheat the oven to 450 F (oiling and preheating will keep your fries from sticking)
3. Spread the fries on the hot pan in a single layer and make sure the pan isn't too crowded, or the fries will steam instead of brown.
Recipes vary for fries - basically I use either potato or sweet potato, cut in wedges, toss with a couple tablespoons of oil, sprinkle salt on to taste. Sometimes I use seasoning salt or other spice. I have also used egg whites instead of oil. The key I think though to make crispy fries is not to cook too many at a time. If you have a convection oven, I would put at least two pans in. With my oven, I bake my fries in 4 batches which is time consuming but worth the effort!