Was your recipe a wet brine? If so I would do a search on the old interweb for Pop's brine. I use a version of it for all of my wet curing. If you don't have an injector I would find one of those. Tractor supply you can pick up a large syringe and a coupe of long 2.5" needles that work well.
Yes, make brine day 1, cool overnight, turkey in brine day 2, cook day 3.
I have an injector, just don't use it.
I loosen the breast skin and rub soft butter with herbs under it.
When temp gets to 160ish in breast, I tent it with foil to let legs,thighs and wings get up to 170.
Breast should be at 165 then.
Here is recipe:
1 Gallon Vegetable stock
1 Gallon Water
1 cup Dark brown sugar
1-1/2 cup Kosher salt or sea salt
NOTE – Omit Salt if Turkey is pre-injected 1/2 cup Apple cider vinegar
1/4 cup Ground cumin
1/2 TBSP Candied ginger
2 TBSP ‘Cracked’ black peppercorns
1 TBSP Allspice berries
2 TBSP Worcestershire sauce
4 ea good-size ‘branches’ of fresh rosemary
Heat until all is dissolved, let cool, then chill in refrigerator overnight.
Next in goes the bird for 24 hours.