I go with my standard turkey formula:
0.6tsp salt (I use morton kosher)
0.2tsp black pepper
0.2tsp dried herb
1 tablespoon milk
per pound of turkey. I dissolve the sugar and salt in milk and inject into various areas of the turkey. I then pat it down with the herb and pepper and let it sit for a day. I'm not particular about roasting temperature. I go as low as time affords. Measure the temp at various locations until 165.
One trick I learned last year was to roast the turkey until it hits 165. I then take it out, pour the juice into a pot, and cover turkey with foil. I gently bring the juices to a boil and then remove the foil cover to the turkey. I inject boiling juice into the thighs alongside the bone. With my thermometer I saw it around 145F and jump to 175F as soon as the hot juice went in. I'm always nervous about bloody meat near the bones so injecting hot juice will ensure those areas are done. Localized "spot cooking" if you will.