Odor is a huge issue. One huge component of odor control is to keep the run dry. A dry run is much less likely to smell. A wet run will almost certainly smell. So your first item to consider is how to keep it dry.
The two things to consider are how to keep water out and how to get water out that gets in. Position it so rainwater runoff does not run into the run. Use berms or swales to divert runoff. Slope the coop roof so water does not run into the run. Consider covering the run, and remember that rain can blow in from the side. You might need to cover the side that has the predominant wind to help keep it dry.
To dry a run, it needs to be higher than the surrounding ground, at least higher than the ground on one side so the water has somewhere to go. You can maybe haul in dirt to build the ground level up. It really helps too if the dirt in the run is porous, like sand, so the water will drain off. The chickens will dig holes in any soil you put in there so they can dust bathe. You need those to drain. Raising the ground level in the run with sand works really well.
Another issue in odor control is size, specificly how many chickens you have per area. I can't give you a magic number. That depends on the soils, your climate, how well it drains, and many other things. If the run is large enough so the poop gets spread out enough, you really don't have to clean much if at all. So actually the bigger it is, the less likely it is to smell. If you can't make it big enough that the poop gets spread out enough to stop the smell, it may be easier to rake out a smaller run.
The other part of run size is chicken behavior. If chickens are crowded, they are more likely to have social issues. Again there is no magic number for how much room a chicken needs. It depends on a whole lot of different things. In general, I find I have to work less hard ands I have fewer behavioral problems if I can provide more space.
Good luck!