The most common staining tools are the basic brush and a piece of cloth. There isn’t much of philosophy to how to apply stain, but some craftsmen paint small objects just by dipping them into the stain can. This is not recommended at all, since it will be messy, difficult to dry, and hard to sand afterward. Not to mention this is not applicable for stain wooden furniture, or any other larger project. So, stick to the painting brush for water-based stains, and choose a cotton cloth for gel and oil paints to spread them evenly.