Apply a thin coat to your finished project with a small rag (large rags waste a lot of oil). After an hour remove any excess oil with a clean rag and apply a 2nd coat with a new rag. Oil finishes takes about a week to fully cure, during which, remove any excess oil with a clean rag.
Oil soaked rags are a fire hazard and must be disposed of properly. I hang mine out to dry on our chain link fence as soon as I am done using them. When dry, I soak them in water. Check with your local authorities for instructions on proper disposal.
I also have a recipe to make your own [[oil_and_beeswax_finish|oil and beeswax finish]]. This finish is a paste and is very easy to apply, dries faster that oil alone and has a nice warm tone. Simply work into the wood with a clean rag and then go back over your work with a clean rag to remove any excess. Follow above instructions for clean up of rags.
Long ago I quite using finishes with harsh chemicals or that required chemicals for clean up. This limited my options. Now there are water based polyurethanes on the market. While they are still not 100% safe for the environment, they are considerably better than the alternatives. As added advantages, you can use most of them indoors and clean up is a snap, just rinse your brushes in water. The water based polyurethanes are not as strong as the solvent based ones, so additional coats are required.
One product I have used is Safe & Simple Clear Poly from Carver Tripp. You should be able to find the Carver Tripp products at your local paint & hardware store.
Begin by mixing the polyurethane thoroughly. Quite a bit settles at the bottom, so this may take some time. Apply the polyurethane with a sponge paint brush. Allow it 45 minutes to dry. Then sand lightly with very fine sand paper, 220 grit or finer. Apply an 2nd coat. Wait another 45 minutes, sand again and apply a 3rd coat. While the final coat will be dry to the touch in 45 minutes, it still takes 24 hours or longer to fully cure.