Use putty filler and a scraper or putty knife to fill in any cracks, holes or imperfections in the furniture. It's best to use a flexible scraper that's wide enough to cover the cracks or imperfections you're filling, so that the putty is applied flat and evenly. Leave the putty to dry.
Sand the furniture using 180-grit sandpaper. For a smoother finish, you could try 240-grit sandpaper. You don't have to remove the varnish completely, just slightly etch the surface so that primer will stick to it. A good tip is to sand in the direction of the grain. After sanding, wipe away any dust with a damp cloth. Remember to wear a dust mask and eye protection while you're sanding.
Mix the primer thoroughly. If you're working inside, you might need to wear a respirator mask. When applying the primer, use a paint roller and make long even strokes. You can also use a paint brush for any areas that are hard to reach with a roller. A handy tip when painting is to lay the paint off before it goes tacky for a finer finish. To do this, go over the surface very lightly with a roller that has very little paint on it.
If you need to apply a second coat of primer, wait for the first coat to dry. Give the surface a light sand with 180-grit sandpaper, wipe off any dust, and then apply the second coat.
For our table, we used a water-based enamel because it dries quickly and is easy to clean. Apply as many coats as you need with a roller or paint brush to cover the area completely. Make sure the paint is dry before applying a second or third coat of paint. Once it's dry, move your revitalised piece of furniture into place and enjoy it for years to come.