If you are in a congregation that says piyutim incorporated into the Birchos Krias Shema, don’t seperate yourself from them by looking into a sefer during the recital of those piyutim (people might come to talk words of Torah which would be an interruption), rather say them with the congregation. (Rama – MB 3)
You may “think in learning” while the congregation is reciting the piyutim. However, during Kaddish it is ossur to think in learning. (MB 3)
When daavening without a tzibbur, do not recite any piyut in the middle of a beracha. (MB 6)
Do not change the minhag of your place in regard to the nusach of tefilla – for example from Ashkenaz to Sefard or the opposite. If you daaven with a congregation of the other nusach, you still fulfill your obligation. (MB 4)