Any tips on moving baby into his own room?

Noona • 🇱🇧💍👶🏻👶🏻🇬🇧

I've been putting him down to nap in his room for the past week but his naps have significantly decreased in length because of it. I used to be able to put him in his cot and walk away and he would sleep but when I do that in his room he just rolls around everywhere and starts playing, until he realises he's being ignored and starts screaming for attention.. does anyone have any tips for the transition?