I am making horse trailer with windows. With SubD, I want to tighten those edges around window, is this good approach and topology. I still have some slight pinching. Thanks!
Window’s visible topology looks fine but the inner windows one is not visible due the subD modifier enabled in edit mode. Where do you see the pinching? (it may helps if you show us some glossy matcap also)?
I wouldn’t say pinching. Just maybe some distortion from uneven size of quads. I am not sure. However I want to check is this “correct” way of tightening edges? I know there is multiple way of doing it.
Best way i found is, like you did with support loops, but subdivide the mesh to final, before cutting any loops. that way the pinching is sort of localized.
found this tut quite good.
This seems similiar like my approach. Bit tiddier maybe, but poly count and edge flow is same. Probably my approach is ok then. Thanks!
Anyways it looks good to me. Obviously it depends on your needs but you could try to do an actual render of it, if it looks good in render it will be a waste of effort trying to achieve the perfection (spoiler: it’s an endless path… 
).
To keep things as it is and simple I’d try just to smooth/relax the tightening edge flow (keeping the last vertex where it is):
It will look good, it’s game object anyway so most of details will be baked. I just wanted to practice topology since I always find “path around” and never actually practice it instead od faking and so on. So I decided to learn it better. Thanks for tips!