1. Remember, in grammatical terms, perfect means completed or finished.
2. Usually, the present perfect tense uses since or for to help in telling us when it occurred:
a. I have lived here since
b. I have lived here for 12 years.
Use since when you are telling us the date; use for when telling us how long.
3. A lot of English speakers use the simple past instead of the past perfect. Compare:
a. Before I came here,
I never studied grammar.
b. Before I came here, I had never studied grammar.
4. Usually the future perfect and past perfect are in need of being set up in the time line with adverbials such as:
by the time... before... etc.
5. Notice the verb tenses:
By the time I turn sixty, I will have had many years of enjoyment.