A clear coat finish isn't your only option for wood stairs. Instead, a range of different looks can be created through staining without putting much strain on your budget. All that is needed is a little application advice and a degree of patience. Here is a simple way to get the rich hues you want for your staircase.
Step 1 - Sand
If you're staining wood that already has a finish, then the first step will be to remove it. Use a piece of coarse-grain sandpaper and gently rub away the outermost layer from top to bottom. If there are some stubborn areas, use a finer grain of sandpaper to handle it. This will create a smooth surface that will allow the new stain to stick. Remove dirt and debris after you have finished using a vacuum cleaner, cloth, and tack rag.
Most stairways have handrails running alongside the steps for safety reasons, and with indoor wooden stairs, these too are usually made from wood that will need to be sanded for a new stain. Wrap the sandpaper around the rails as well as an spindles and rub up and down repeatedly, working the paper into smaller crevices as needed.
You can skip this step entirely if your staircase is new and/or unfinished.
Step 2 - Apply Stain
Protect all areas you do not want to stain by covering them in masking tape, and lay down sheets of newspaper to stop any additional splatters from hitting the floor. Then, wet the wood with a small sponge, as this will help the stain spread evenly. You will likely want to work in small sections, such as one step at a time, so the wood doesn't dry out during application.
Use a small angled brush to gently paint a first layer of stain on the top and side of each step. Move in the same direction as the wood grain. Wait for this initial layer to dry before using a larger paintbrush to add more stain to the rest of the step. You can repeat this process several times to get a darker color effect if that is what you want.
Step 3 - Add Stain to the Handrails
Either wait until the stain on the steps has dried or use a small ladder to access handrails from the other side. Wet the entire length and the spindles a little at a time. Apply a small amount of stain to a large cloth and rub in the direction of the wood grain once more. Allow everything to dry before you add any subsequent coats for your desired color.
Step 4 - Address Any Patchy Areas
Any areas that are visibly lighter than the rest of the stairs will need another small layer of stain. Apply this before the rest dries. This is important because it will prevent your work from looking patchy and unprofessional.
Step 5 - Varnish
The final step is to apply a thin layer of wood varnish to everything. Wait until the stain has dried and use a small paintbrush to spread the varnish to all areas that have been colored. This will give your wood a glossy appearance. This is important because the varnish will help seal in the depth of color that you have created throughout the staining process, and create a protective layer that will keep the effect in place for many years to come.