3 way mitre in window reveal

[Noodles01]

Hi, I am at a complete standstill, just cant get my head around the corner joint I need to do in the window reveal. So I am just tiling 3 tiles up the reveal and have followed tutorials on "how to do a 3 way mitre" but it just doesnt work for me. Is it that the trim I am using is just rounded and not a full quadrant and will therefore not work? If so how is the job done neatly? The only way I can see it to mitre the 2 horizontal trims 90 degrees and then butt the vertical up to them but it doesn't look tidy as you then have a curve meeting a point?

Can a ready made curve be bought that suits this trim? the ones I see seem to only be for quadrant and would therefore not work with my trim?

If anyone could point be in the right direction I would be so grateful.

Thanks in advance!!

 

[Wesley]

Try 3 way mitre, mancave projects, on YouTube.
Couple of practice cuts on scrap trim and you’ll be away

 

[Wesley]

The important bit is : where you place the trim when you’re cutting it.