diff --git a/docs/introduction-to-smart-contracts.rst b/docs/introduction-to-smart-contracts.rst
index bfce0d5a3..8675474a7 100644
--- a/docs/introduction-to-smart-contracts.rst
+++ b/docs/introduction-to-smart-contracts.rst
@@ -388,7 +388,9 @@ Each account has a data area called **storage**, which is persistent between fun
 and transactions.
 Storage is a key-value store that maps 256-bit words to 256-bit words.
 It is not possible to enumerate storage from within a contract and it is
-comparatively costly to read, and even more to modify storage.
+comparatively costly to read, and even more to modify storage. Because of this cost,
+you should minimise what you store in persistent storage to what the contract needs to run.
+Store data like derived calculations, caching, and aggregates outside of the contract.
 A contract can neither read nor write to any storage apart from its own.
 
 The second data area is called **memory**, of which a contract obtains