Minimising number of queries on a page when using Advanced Custom Fields

Question

I'm currently working on a site where there is extensive use of the popular Advanced Custom Fields plugin. However, as a result the page loading time can be quite slow, especially when using the Gallery plugin.

Does anyone have suggestions regarding what the best practice is with managing a large number of custom fields? In some cases I am effectively working with thousands of variables, and need to reduce the page load time from some cases around 5s.

Quite an open question I know, though really it would be great to have some suggestions regarding how number of queries in a page can be minimised (such as through directly accessing values in the database perhaps rather than relying on a plugin's APIs?).