SQL Server - SQL Plan Management for baseline
You would just pull the execution plans for the most relevant queries from the plan cache.  I would query sys.dm_exec_query_stats, and join to sys.dm_exec_query_plan and sys.dm_exec_sql_text to get the plan and query text, respectively. Within sys.dm_exec_query_stats you can pull queries with the highest IO, CPU, execution count, etc. - whatever is most important to you.

Looking to the future, SQL Server 2016 introduces the Query Store:

Monitoring Performance By Using the Query Store