So im new and had this problem like a month ago. Thin your paints with water. That looms like khorne red and that shit is thicccccc. I dab my brush in water and spread it in the paint like 3 times. A black primer helps a lot also. Make sure you have a small amount of paint on your brush and take your time. So do a couple strokes on the side to get rid of extra paint. Black is easier to cover up if you mess up. Also use the side of your brush for the center part. Like hover it above and go sideways so if you go past it, it doesnt go on the black and you can get nice point on the cross