If you are seeing processes block themselves, you need to review what type of waits you are encountering. My guess would be that they are CXPACKET waits - which means the queries are using parallel plans.

To reduce the parallel plans and blocking you need to focus on fixing the queries.

You can also reduce the impact by setting the max degree of parallelism setting for the server to 1/2 the number of cores. Reduce even further if you are still seeing a lot of parallel plans and they are causing issues.