So your thinking of using a DTR device but are unsure where to start.
To use the DTR or Retainer device some shaft skin is needed. The more shaft skin available the better.
In the restoring world you will see a term called the ” CI-index” used often. This Coverage Index is based on how foreskin or loose skin a person has. Click here to see the CI index chart
Almost every man that restores starts with a CI 1 or 2 on average , Consider yourself very lucky if you have more than a CI-2 when you are starting.

First Thing you will want to check is your glans width when flaccid.
Most DTR users will fall between 30 to 40 mm wide when flaccid. (1.8 to 1.5 inches )

Second thing to check is if you still have any frenulum left.

If you have any frenulum you will require a notched push plate should you decide to use Dual tension.

Another option you will see is gripper choice, Grippers with holes are a little more flexible since there is less material
Its seems to be a 50/50 with people using grippers with or without holes. so it really is just a personal preference.

Most men start restoring by using the Tug method with a strap as this requires the least amount of skin when using a device.
A CI-index of 1+ is needed for the tug method.

Manually stretching the skin is also another way to start.
Loosening the skin is the first step in the process and this normally takes only a few days to a week making using a restoring device an easier to do.
I had trouble when I start to restore for the first time. It can feel awkward at first. You will get erections when trying to attach a device. This happens to most of us. After a few days my body became used to the idea of having something attached to it. The erection issue when installing a device diminished as will the awkward feeling of having something attached to my penis.