And if you or anyone else wants to play with some UPG of mine developed from working with demons in recent months, try a six-sided (hexagonal) piece of thick black board or black-painted wood in place of a triangle - do NOT be tempted 
to draw in a Star of David inside it, you want the solid shape with no markings or names.
Like this, straight side (not angled point) facing towards you, unless you’re guided to do it differently:
You can place it on the ground, a table, whatever’s relevant with your set-up, but in this method I’ve been told to not use any other symbols that may impact upon it (so, don’t place it on a circle of godnames like a traditional goetic circle, or on a cloth that has any symbols of any kind) - it’s a standalone piece that contains its own cosmogony.
I’ve been told demons will find this particularly welcoming for those of us who don’t default to constraining them, but usual disclaimers apply that this is my UPG only - I’m sharing it in case you find the triangle idea still too redolent of methods you don’t like.