It's almost a given that after completing a major project that you'll wish you had done something differently. A recent post by Rich Adams at Weblinks covers a bunch of rookie errors and advanced options that will help you optimise your AWS deployment.
The list of items at Weblinks is quite extensive and covers everything from naming buckets using "-" rather than "." in the name through to how to set up billing alerts and how to optimise certificate deployment on load balancers.
If you're contemplating or planning an AWS deployment then this is well worth a look.
AWS Tips I Wish I'd Known Before I Started [Weblinks]