Before you start staining, you need to make sure that your hardwood floor is sanded properly. Hardwood flooring stain will show all of the imperfections in the sanding job you have done. Areas in the hardwood that are rougher will stake the stain darker, just as areas in the hardwood that are smoother will take the stain lighter. The most common problems with sanding a hardwood floor before staining is the areas around the perimeter that were sanded with a flooring edger. You need to have your edger technique down so you remove all of the swirl marks.
Once you are sure the wood floor is sanded properly, you need to remove all of the dust from the floor. Make sure there is limited airflow in the room, so turn off and forced air heater or air conditioners, close windows, and make sure ceiling fans are off. You are now ready to start vacuuming. Before I hit the wood floor, I usually go around the room and vacuum the window and door sills, and any other ledge type areas that could have dust on them that could later fall to the floor. Then vacuum the wood flooring thoroughly. After you are done, vacuum yourself off paying special attention to your shoes and your pants, basically anything that has touched the floor.
You’ll want to make sure you have non-marking shoes, or booties over your shoes. Do not walk on an unfinished hardwood floor with only socks on. The condensation/sweat your feet make can soak into the wood, opening the grain which will allow the stain to penetrate deeper and leave you with a darker color.
You’ll also want to have good gloves on at all times. Stain is stain, and it will stain! It will stain absolutely everything, so gloves are a must. I even like to wear clothes that are surely to end up as rags at the end of the process just to be sure.
I also like to prepare a trash bag exclusively for items like rags, gloves, buffing pads, and brushes, used while staining hardwood floors. Stain rags can be combustible, especially when mixed with saw dust. When the hardwood floor has been stained, take all those items and immediately throw them away outside. It also helps to soak them in water on the way out to the trash.
You are now ready to stain your hardwood floor.