When routing all but the very smallest profiles, it works best to make multiple, light passes. Taking light cuts will minimize chipping, leave a much smoother surface. The depth and number of passes is determined by the size and shape of the profile you’re routing and the type of wood.
There are two techniques for taking multiple passes — you can raise the height of the bit between cuts, or move the fence back, exposing more of the bit. I prefer the latter approach. For starters, it’s easier to move the fence than to change the bit height. And once the bit height is set and tested, you’re assured of an accurate depth-of-cut.