Make sure that clicking any link on the site results in a correct URL request. On-site clicks should not result in a redirect.
Make sure that the rule target includes the protocol and hostname. Order all of the rules such that no request results in a multiple step redirection chain.
Beware of "case doesn't matter" URLs. Every resource should have a single or canonical URL with specific casing. Incorrectly cased requests should be redirected. This can be quite easily done as the first function within the PHP or other script.