Are questions* like "Does my phonology look naturalistic", "How can I improve my phonology (to make it look more naturalistic)" and "How can I evolve my phonology" allowed here? It seems, at first glance, that these type of questions are too subjective, but investigating what's wrong with a phonological system is educative.
Naturally, simple answers like 'do this' are wrong, and answers should not contain what to do but how to do it, talking about kitchen-sinkness, balance in phonological systems (and mass changes and chains that might occur there), phoneme occurence in systems and Euro-/Anglocentricism.
How natural my phonology?
This is my phonology for my language examplang.
PLOSIVE | p b | t d | k g |
NASAL | | | |
FRICATIVE | f v | θ s | x |
APPROXIMANT | | ɹ | w |
FLAP/TAP | | ɾ | |
| i y u
| ɛ ɔ
There are a couple things to notice. First, balance. The only voiced fricative is /v/, which is very unbalanced (although there are exceptions [with link]) and via sound changes, it might be removed or other voiced fricatives added. Then, the only front rounded vowel is /y/ and the Close-Mid row misses a back.
Then, occurrence. Less than 2% of languages have no nasal stops (Maddieson, Ian. 2008. Absence of Common Consonants. Accessed online at http://wals.info/feature/18). Also, /j l/ look quite common in a system like yours.
Common sound changes to evolve your phonological systems are: a chain in the vowels (which partially will fix irregularities), voicing when intervocalically (Old English had /f s ʃ h/ (or /x/), and borrowing /v/ from French added /v z ʒ/ due to balance), adding diphthongs via gemination (i.e.
Vr > V[+gem], then
a: > ai,
e: > ei,
ɔ: > o(fixing unbalance),
i: y: > i(later inducing merger between /i y/ too) and use those diphthongs to get glides).
A different question may have been answered including Anglo-/Eurocentricism, kitchen-sinkness and relex.