My typical work flow on the desktop when making selections is turn on the quick mask, use a round brush to paint an outline of what I want to mask out, fill that outline with the bucket tool, turn off the quick mask and there you have a selection exactly the way I need it. Quick and painless...
Here is my experience with this process on the iPad Pro 12.9
I select my image layer. I go to the selections persona and... where is the quick mask? I spent an hour searching the internet and the tutorials I can't find it. Where is the regular old paint brush so I can paint in what I want and don't want to select? I can't find one so I try the tools available.
I click on the smart selection brush tool. It selects the object but the edges aren't what i need. It's just not a clean selection. I try the refine edge but it makes the refinement for you. I can't figure out how to just paint in and out what I want when in refine mask. Again why is there no regular round paint brush?
I start over. I click on the flood selection tool and when I run my apple pencil over the image it does nothing. When I run my finger over the image it does nothing.
I switch to the select colored sample tool and when I run my apple pen over the image it does nothing. When I run my finger over the image it does nothing.
I switch to the Polygon marquee tool on freehand. I draw with my apple pencil around the object I want to select and it actually selects it! Success!!! I turn the tool to "subtract" and when I put my apple pencil inside the selection I just made, in order to deselect a section of it, all it will do is move the selection around the canvas. Same results with my finger. While on free hand the tool will only let me subtract a section if I start the selection outside of the previous selection. grrrr.. seriously?
I deselect everything and decide to start all over. I finally locate the quick mask feature. Now were cookin' I turn on the quick mask under the selection persona. But where is a regular brush I can use to paint on the quick mask? Since there is no brush tool in the selections persona I get out of the selection persona and back into the photo persona pick up a white, hard edged brush. I find I can't constrain the paint brush to draw a straight line. Never did figure it out... I outline the object as carefully as I can on the quick mask with a white brush. I pick up the bucket tool to dump the white into the outline on the quick mask but it won't dump white. It will only dump black and it covers up the outline I just created. O.M.G. -
Since I have a quick mask "outline" of what I want to include in my mask I decided to use the selection persona's polygon tool to select inside my outline so I can mask out the rest of the object. The polygonal marquee tool doesn't do anything when quick mask is on. The only selection tool that works on quick mask is the smart selection brush!!!! None of the other tools work when its on!!!
I turn off the quick mask so my outline is turned back to the marching ants. I FINALLY figured out if I use the polygon marquee tool on the polygon setting to select the inside of the object I outlined in quick mask that I can finally get the selection I want. The polygon setting on the the polygon selection tool is the ONLY setting I can find (with that selection tool) that will allow you to add and subtract to your selection when you are selecting inside the borders of a previous selection.
When it comes to this app I must be a dum-dum because I suck at it. I have never in my life... I need a beer... There has got to be an easier way. Please tell me there is one...