What is the best reporting technique?

What is the best reporting technique should I use with crystal reports and SQL server to get the best reporting performance?
- use SPs?
- summary information should be summarized in the SP first or summarized in the Crystal report?
- if I want to do some calculations, should I use any temp database in the client machine? (access db for example)? or I may use the SQL server temp db?
- can I easily isolate the temp db per user?
- does the temp db increase the log file?

Thanks

Use sp, but make cristal report do summarization.