Attempting to answer only the actual question here - so forgive me if there are some cultural nuances that I miss with respect to the ethics of some person of unknown race wishing to add this beautiful dialect to their dialogue.
Writing in AAVE/Ebonics/African American Dialects is very difficult to do well. My advice, first and foremost, is to read some of the authors who have used this language successfully and study what they do. Faulkner, Morrison, Dunbar, Hurston and Baldwin all have managed to meld these dialects with their fictional worlds in a way that adds to the reality of their characters rather than reduces their characters to a specific racial viewpoint.
Written AAVE and spoken AAVE differ in a variety of ways, it's very easy to go 'overboard' with AAVE in writing and seem like you are creating racialized caricatures instead of race-conscious characters. If I might posit a golden rule from writing in AAVE - too little is always better than too much.
The second thing you need to think about is why you are using AAVE. Is there a reason your characters need to sound a particular way? Is AAVE a subtextual signal of a lack of privilege? Is it used to group people in a particular way? What do those groupings signify? Would you be comfortable just coming out and saying why you are grouping people? If not, AAVE may be the wrong tool for the job. Using non-standard vernacular english to engage in racialized groupings of characters and ideas is not something I'd recommend.
So when should you use AAVE? I think some scenarios where it is appropriate include when you are writing to a privileged audience and want to help them traverse that white privilege and empathize with characters and ideas that would otherwise seem distant to them. AAVE is a powerful tool for forcing readers to give voices to the characters, it demands verbalization and expression - it cannot be skimmed or glossed over by white gazes, instead it confronts whiteness and demands acknowledgement and, to some degree, agonistic empathic connections.
Now that we have a sense of when to use AAVE, what about the how? Here are some 'general rules' - remember AAVE is invented and constructed by the author so there is not right or wrong (just like with all written fiction), just always be sure the choices you make adhere to a larger goal of communicating something through form that the content of the text alone is unable to communicate.
These distinctive Ebonics pronunciations are all systematic, the result of regular rules and restrictions; they are not random 'error'--and this is equally true of Ebonics grammar. For instance, Ebonics speakers regularly produce sentences without present tense is and are, as in "John trippin" or "They allright". But they don't omit present tense am. Instead of the ungrammatical *"Ah walkin", Ebonics speakers would say *"Ahm walkin." Likewise, they do not omit is and are if they come at the end of a sentence--"That's what he/they" is ungrammatical.
Ebonics pronunciation includes features like the omission of the final
consonant in words like 'past' (pas' ) and 'hand' (han'), the
pronunciation of the th in 'bath' as t (bat) or f (baf), and the
pronunciation of the vowel in words like 'my' and 'ride' as a long ah
(mah, rahd). Some of these occur in vernacular white English, too,
especially in the South, but in general they occur more frequently in
Ebonics. Some Ebonics pronunciations are more unique, for instance,
dropping b, d, or g at the beginning of auxiliary verbs like 'don't'
and 'gonna', yielding Ah 'on know for "I don't know" and ama do it for
"I'm going to do it."
In Ebonics, be refers to a continuing state of being. The Ebonics sentence. "I be angry" is the same as the standard English "I have been angry for a while" and is grammatically correct.
Ebonics leaves out forms of to be in cases where standard English would use a contraction[...]Ebonics also often drops -ed from the past tense and lacks the possessive 's[...] Consider the sentence "I don't want no trouble," which is of course, commendable [...] double negation is acceptable in Ebonics.