Basement bathroom rough-in

I am going to try to rough in a bathroom basement, but I am not too sure how to proceed on some of the drainage because I am new to working with a slab. Here's my questions:

1) For the toilet rough-in, am I supposed to use some sort of collar or tape around the stub where the concrete will touch the pipe to keep the pipe free I guess?

2) For the bathtub rough-in, I am not sure how you get the 4x12 cut-out for the p-trap area...are you supposed to use a wood form or just cap off the pipe under the tub area and then come back after you have poured the slab and break out that area?

Any info would be appreciated.

If yr slab has not yet been poured, it's best to plan out as much of the pipe layout as possible and lay that first. Some people use a plastic box around the traps only to allow manipulation and precise placement of the fixture after the pour. If you use a wood form, make sure it has a lid so you can cap it until you finish the rough in.

You don't need a collar around the toilet stubout once final precise placement is determined. in fact my inspector REQUIRED me to cement it in place - cement right up to the pvc to prevent any shifting.

Use a collar cap for the toilet riser. Make a 12" square tub box. You cut a slot in it so it rests on the pipe, and the top of the box is even with the finished floor.