Forming Kerdi over CBU

I am currently doing my second tub surround in our house. Also my second tile job.
Last year when doing the first one I had a problem getting the Kerdi to form sharply folded corners over the CBU and I envision the same problem again. I have bought the preformed inner and outer corners but hope to use strips of Kerdi rather than the Kerdi-band (our small town supplier doesn't stock much, took 2 weeks to get the corners)
Does anyone have any tricks to sharp corners such as prefolding and ironing the strips of Kerdi?
I have a window recess and a 6" full length shelf behind the tub as well as the normal two back corners to contend with.

First of all the KERDI Band is much thinner than the KERDI Mat. To cut you own (bands) will cause additional thickness (bumps) you don't need.

The KERDI Mat can be pressed into the corners with a 6-10 inch broad-knife and if the proper amount of thinset has been applied they will stay in place and the corners will be sharp.

Thanx Bud. The things the dealer never tells you. Called them back, got another girl who mentioned that their truck is going to the wholesale tomorrow. They can have a 16' roll back here for me by 5pm. ($25). Neighbour (its his tile saw) is coming to help on Sunday so it should work out.
PS- Keep up with helping us duffers, your advice always makes things easier.

Just between you and me I think the prices of all the Schluter products are totally ourageously high. The thing is they still have the only game in town in some cases.

I too have tried to use home made KERDI Mat strips and the truth is, it isn't worth the trouble and the problems it causes. I'll continue to pay the price and make it up somewhere else.

Schluter and Noble are the best things going right now.