Well love,
I wouldn't use the guides as they only tend to mess up polishes and that includes the More Than White Acrylic.................
I am afraid practice is the key here................
practice with normal white polish to get a nice smile line...on a tip...........
You can perfect the line of more than white with a fine brush dipped in nail fresh............. it's brill and is used in competitions on normal enamels all the time...........
just keep practicing.............
love Ruth xxxx
P.S. if you do a search on french polish they will be some help in how to apply a perfect french and this tip would also cover the More Than White technique..............