How to Reserve seats with Eurail pass apart from Eurail reservation service?

Hello Eurail/Interrail Experts,

I am travelling with my parents in Italy for a week commuting between Milan - Rome - Pisa - Venice.

is there a way to Reserve seats with Eurail pass apart from Eurail reservation service? 

I am trying to avoid the extra reservation fee by Eurail. 

Thanks in advance! 😀