The best way to setup your development framework?

I see a lot of developers using a special setup for server/client communication with Module scripts nowadays. I'm not sure what the best setup is for all this. I also see a lot of events that have functions connected to them to connect and discconnect them. I just get confused on what the most "Clean" and professional way to code a game on roblox. I know using module scripts for OOP is handy. But I just see a lot of these frameworks that confuse me and stuff