I'm designing a metal mould for my CFRP project having approx 400mm height.  Can anyone please help me with draft angles because I couldn't afford much deflection in it. What kind of welding should I prefer for it?

On CNC machined moulds I use min. technological draft 2°.
If the mould is welded, based on sheetmetal parts or something similar, be very carefull about inner tension caused by welding. The best is TIG and design very stiff and strong support frame. If the mould is machined after welding, there is a highly recommended make roughing - high temp.stabilization - finishing - polishing.
If possible, use cold joints...screws, bond, rivets etc...instead welding.

Generally I prefer splitting the mould where draft is needed
Depending on the shape of course, although until now I always figured out a way to avoid as many drafts as I can

Splitting the mould and using screws to clamp them is my prefered way, enables complex shapes with zero release problems

Thanks for the reply sir. Welding will be done at one of edges where three faces join. Also the edges would have a fillet of 20mm. Could you suggest a better option for the edges.