Reset SQL Server usage
Short of restarting the SQL Server service or the box this is enough. If you want to be absolutely fresh you might want to drop user created statistics from your last run.

SELECT stats.name, objects.name, schemas.name,objects.create_date
FROM sys.stats
JOIN sys.objects ON stats.OBJECT_ID = objects.OBJECT_ID
JOIN sys.schemas ON objects.schema_id = schemas.schema_id
WHERE stats.stats_id &gt; 0
  AND stats.stats_id &lt; 255
  AND objects.is_ms_shipped = 0
  AND auto_created = 1
  order by objects.create_date desc