Please read this so you understand the standard types of lighting available. http://m.inspectapedia.com/?url=http%3A%2F%2Finspectapedia.com%2FBestPractices%2FLighting_Interior_Guide.htm#2612
A trim where the bulb is flush with the ceiling usually works best with an R or BR type bulb. It provides concentrated light where needed as well as ambient light. Not so good for 8' ceiling, as the light is too close and glared a bit. 9' or higher ceilings are better for this. Wide angle baffles let the light spread out further provided you are using a flood lamp. They stop the side glare a bit especially if it is black. Narrower baffles cut the side glare the best, but are only good for direct lighting of a small area. There are several different combinations of bulbs, trims, and how high in the can the bulb sits. You can create different effects with the same trim.