Makeup is really the best way to conceal acne scars - it doesn't reduce your manliness to use it. But if you really object, use flesh colored Clearasil.
It is quit hard to do it without make up but I used to wear clothing that has some dark color i.e brown or green rather than some light color and this will hide it.
There are pimple products that men can use that have a tint in them. They will help hide redness and minimize contrast. You can find these products in any store that carry's health and beauty supplies.
