When sharing a deck its always very helpful if you post your main strategy(ies) and your opening. Could you post them?
After 15 siren games with this deck you probably have more experience with her than most people. You should be the one giving tips. 
How did it go? What was your weakness?
My opening is a little slow but it goes:
1) Ring of Oceans Depths, Naiya
2) Naiya moves and casts Echo of the Depths, mage casts Harmonize on Echo and moves into same zone as Naiya
3) Mage casts Shallow Sea in center, Naiya casts Ring of Tides, both move into the central square with Shallow Sea
From here Naiya summons my equipment. After that I tend to use her mainly for casting enchantments but it depends. The idea behind having your mage in the center is so you can cast Sirens Call and use your Trident as much as possible. Don't forget that Sirens Call can be used on your own creatures.
It's very important to try to get Shallow Sea in the opponents center. Bed of Urchins works really well in Shallow Sea areas but I wouldn't use it in a zone without one. Coral Barrier serves two functions. Firstly, it blocks of the side flanks, forcing enemies down the center of the board. Secondly, it's pretty much an auto cast once you get a Harpooner out since the synergy is too good to ignore.
I've included Meditation Amulet so that when you can't attack with your Trident you can gain mana, but always use the Trident if you can.
No matter who I'm playing against the Tidecallers rarely seem to be a bad thing to summon, but try to summon them when you don't have the initiative.
This Spellbook is a little slow, but if you're rushed you and Naiya can cast Surging Wave to buy you some time.
