Yet another LDR placement question

[Ctrl4Smilerz]

I'm getting ready to place the LDR/LED in my General Tso build and want to make sure I do it correctly. My plan is to the LED touching the LDR, and then cover it a tube of shrink wrap like this:

I'm thinking of mounting it like this :
View attachment 3912

Should I heat the shrink wrap tight, or just tight enough to block the light out?