There are many admixture with ayahuasca, some sort of traditionnal inthe amazon some more experiemental. However it isn't necessary safe, especially for a beginner.
Some good and benign one are : ilex guyasa - gives an awaken feeling to aya, as it contained coffein and lots of anti-oxydants (no side effects) and said to help lucid dreaming.
Cat's claw is also another very medecinal herb that can be add, it helps the immune system, thus maintening you in good condition.
Psilocibine mushroom is a great one admixture too. You can even mix with chaliponga low dose.
same goes for salvia divinorum, smoked or quidded (or sublingual solution).
You could add some rue or passiflora to synergise the harmalas, also some caapi leaves.
After that changing dosage of both caapi and admixture change quite a few things.
Good luck !
Smell like tea n,n spirit !
Toke the toke, and walk the walk !