Switching to Mixed Grip

I have just started training the big 3 and I have been told that if I want to pull any significant weight without grip failing, I have to switch to mixed grip. This just feels un-natural to me as i don’t feel like i can contract my very well, at least, not as well as over over.

Any tips on how to improve lat contraction in the mixed grip, or any way to us over over grip (without straps) whilst handling significant weight?

Hook grip is pretty much your only option if you cant mixed

Is it supposed to feel off to begin with?

well with any technique change in lifting it is going to feel off for a bit takes time and practice

You get used to it. To get tight lats I use the ‘crush an orange in your armpits’ cue and that works just fine for me with mixed grip.