The spread pass is a nice pass, however it does have its angle problems. It has a time and a place. IMO the best pass to learn is simply the classic pass. It seems to have the most possibilities in terms of times to use it while keeping the actions natural.
Here's what I've always told people who want to learn the pass to do:
Take a deck of cards, and practice the classic pass. My practice routine for the pass was this:
1- Do the pass slowly 30 times. Extremely slowly. Watching for any points at which the deck scrapes, any flicker points, any slight mis-steps. Iron out these kinks. Do it 30 times until you dont see any.
2- Do it again 30 times, but at medium speed. If you EVER slip up or hear a noise... start your count back at 1. You have to do 30 perfect passes to get to step 3.
3- Same as step 2, but at full speed.
4- Restart at 1, run the cycle again. Do this about twice a day.
Do this every day for a week. At the end of the week, add about 10-15 cards to your deck. Do this every week; adding cards until you're up to passing 2 full decks (without any noise or flashing). You're now ready to go.
It should be noted that after you've started adding cards to the deck, until you've reached the 2 deck mark DO NOT go back and use only 52 cards EVER to "see where you're at". This is working backwards. You want to make your pass better? Then keep going until youve gotten to 2 decks. Don't work backwards.
This may seem extreme to some of you, but I GUARANTEE you that if you do this, you'll see huge improvements on your pass. I constantly get compliments on my pass from magicians and this is the exact reason it is so smooth.
After you've got the classic pass down, start opening your fingers up as you do it, make it as fair as possible. Slowly add a riffle in there. Play with retaining the bottom card for an essentially angle proof pass.
tl;dr? You wouldn't have done what I told you to do anyways. Don't worry about it.
Cheers,
Lucas