Before you start, give your tiles a good clean. You want to make sure the area is clear of any dust or debris around the tiles.
Cut the silicone nozzle at a 45° angle so that the silicone runs smoothly along the surface of the join. In this case, we are using a grey coloured silicone along the base to match the floor tiles and a white silicone up the wall to match the wall tiles.
Put your silicone container into the caulking gun. Apply the silicone generously along the join, starting from the centre and working your way out.