The best application method depends on the gel stain, each manufacture is a little different. I like Old Masters gel stain and find that a good White China bristle brush works great. Also, I have used a Ox Hair/ White China combo with good results.

It also depends on what you are staining. New wood is easily stained with a clean white soft rag dipped in the stain. A fiberglass door is best stained with a brush, more control.

Here’s some general rules to follow to apply gel stain for a smooth and professional finish:

Preparation:
1. Clean the surface: Ensure the surface is clean, free of dust, dirt, and any previous finishes.
2. Sanding: Lightly sand the surface with fine-grit sandpaper to create a smooth and even base for the gel stain to adhere to.
3. Test application: Always test the gel stain on a small, inconspicuous area to ensure the desired color and finish.

Application:
1. Stir the gel stain: Thoroughly mix the gel stain to ensure an even consistency.
2. Apply the gel stain: Use a high-quality brush, foam brush, or rag to apply a thin, even coat of gel stain in the direction of the wood grain. Avoid overloading the brush to prevent drips and uneven application.
3. Wait and repeat: Allow the first coat to dry according to manufacturer’s instructions. Apply additional coats if a darker color is desired, ensuring each coat is applied thinly and evenly.
4. Finish with a topcoat: Once the final coat of gel stain has dried, consider applying a topcoat such as polyurethane or varnish to protect the stained surface and enhance its durability and sheen.