Rugs, Carpets and Carpeting - Cutting carpet into closet, tips?

I am installing new carpet into one of my closets. The closet is about 2 foot deep and 8 foot long. The issues are that there are 2 bump outs in this closet so it's not a perfect rectangle. And even worse, the long back wall isn't straight so I can't even start out with a perfectly straight cut against it. The siide walls aren't perfectly square either.
So in the end I have to cut it all by hand. I would appreciate any advice.

BTW, it seems to be the "normal" thing around here to leave the shoe molding on in closets since padding isn't used under the carpet. So the carpet is just butted up against the shoe molding, and that is what I have to do with the new carpet.

FWIW, the carpet is a piece of scrap taken home from a Kohls department store renovation, so it's some type of commercial grade carpet I assume.

Do you have baseboard in the closet as well? Or just shoe? What kind of flooring?

If base and shoe, and a wood floor. I'd pull the shoe, push the carpet to the base, staple to the wood floor, then re-install the shoe.

Either do a template with brown paper , or cut it slightly oversize, push it into the floor/wall joint and trim it, then staple down and install shoe.

Just a DIY'rs suggestion..I'm sure a Pro may have a better way..but thats almost the way I did my first sheet vinyl install a few months back and it works and looks great.

Thanks for the reply!

I have both base and shoe, but I really didn't want to get into taking the shoe off.

The template idea sounds good.