This topic has been covered a bunch here in the forums, I'd strongly recommend searching the forums for some advice.
Some example publications include 6 tips to make your dashboards more performant | Tableau Software
Hi Clay, in addition to Clay's advice of searching the forums and looking at docs, the top three things I'd suggest are:
- Filter out practically as much data as you can before it gets to Tableau. Use SQL filters, data source filters, etc.
- Work with published Server data sources (that are extracted and refresh on a schedule).
- Break up workbooks into as few sheets/dashboards as practical. Using published data sources makes this a lot easier to maintain. Less complex books are almost always more performant, all else held equal.