What program are you using? I may be able to help :)
(Ill take a look at the examples once Im not on a school device....but here are some general tips:
When cutting out a horse, I use the lasso tool to make a basic outline around the horse, and cut out BG. Then I zoom in really closely, and use a soft round brush to cut the horse out. Make sure to take your time and be patient.
Honestly, I would not suggest premades. Often times, theres a ton of stock rules about them, and you can only do so much with a premade, and premade manips dont normally sell well.
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Two stock image sites I suggest are DeviantArt and Unsplash. Unsplash is totally free, and most of DeviantArt stock is free.
Some horse stock providers I'd suggest on dA are:
Chunga-Stock
Eltear Stock
Celtic Stock
fillyrox
xxMysteryStockxx
venomxbaby
jello88
And theres a lot more too!
My dA is SNCMustangs, and if you go to my favorites, and choose the "Stock" gallery, theres a good amount of stock there.
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Also, I would very much suggest IbisPaintX. It is a great app, and has really helped me improve in both digi painting and manips :)
Edited at November 20, 2020 10:22 AM by Ethereal