In conversation, it’s easy in the midst of spontaneous speech to succumb to verbosity and duplication. In writing, redundancy is less forgivable but fortunately easy to rectify. Watch for these usual suspects:
1. Absolutely certain or sure/essential/guaranteed: Someone who is certain or sure is already without doubt. Something that is essential is intrinsically absolute. A guarantee is by nature absolute (or should be). Abandon absolutely in such usage.
2. Actual experience/fact: An experience is something that occurred (unless otherwise indicated). A fact is something confirmed to have happened. Actual is extraneous in these instances.
3. Add an additional: To add is to provide another of something. Additional is extraneous.
4. Added bonus: A bonus is an extra feature, so added is redundant.
5. Advance notice/planning/reservations/warning: Notices, planning, reservations, and warnings are all, by their nature, actions that occur before some event, so qualifying such terms with advance is superfluous.