General synonyms:
* Overused
* Clichéd
* Banal
* Hackneyed
* Commonplace
* Stale
* Unoriginal
* Insipid
* Uninspired
* Mediocre
More specific synonyms:
* Platitudinous (expressing commonplace ideas in a pompous or dull way)
* Stock (conventional, lacking originality)
* Formulaic (following a predictable pattern)
* Shopworn (worn out from overuse)
* Timeworn (old and outdated)
* Faded (lacking freshness or originality)
* Bland (lacking in flavor or interest)
* Superficial (concerned only with the obvious or apparent)
The best word to use will depend on the context of your writing. For example, if you're describing a piece of writing that is full of overused phrases, "clichéd" might be the best choice. If you're describing a person who is always saying the same old things, "platitudinous" might be a better fit.