I suck at math. Tell me if I did this right.

I hit an election day sale today to buy shoes using a combination of several different coupons.

I had one coupon for $10.00 off any $50.00 purchase.

I had one coupon to save 15% off "today's price".

I bought one pair of shoes for $45.00, the regular price.

I bought a second pair of shoes for $22.00 + 25% off. ($15.50)

I presented the coupons in this order:

15% off: ($45.00 - 15% = $38.25), plus ($15.50 - 15% = $13.25)

$38.25 + $13.25 = $51.50.

Then I gave them the $10.00 off a $50.00 purchase coupon so I got both pairs for $41.50 instead of the $67.00 regular price.

Since I totally suck at math I'm wondering if I could have figured out a better deal. Could I have saved more than $25.50?

Please note: I suck at math, it's late, I've had a glass of wine, there might be mistakes in my above calculations. My real question is what is the best way to combined coupons to get the best deal? Is there some kind of system?

Also note: this is not homework; I'm just trying to figure something out and I suck at math so I'm asking here.

Thanks!