As I've been going over the Jarda documentation, I've been wondering 
whether it might be better to use digraphs or extra letters in some 
cases where I'm currently using diacritics. In particular, I don't see 
any reason not to use "gh" for [ɣ] instead of "ğ" (it's too easy to 
confuse "ğ" with "ģ"). And I'm still unsatisfied with the way I write 
the voiced lateral fricative as "ḽ" (l with a wedge below), but I can't 
think of a suitable digraph. I can't use "dl" since /dl/ is a valid 
cluster (e.g. dlôź "month"), and "ll" exists in compounds (e.g. trillaz 
"Year of the Wren").

I've gone back and forth on how to represent the sounds of my languages. 
Although many of them (like Jarda) have their own writing systems, it's 
tedious and error-prone to use those for the actual language 
documentation. I almost always use some form of Roman-alphabet 
representation. Lately I've been leaning in the direction of diacritics, 
which have the advantage of being able to create "ad hoc" letters for 
unusual phonemes. It's also good for series of related sounds, e.g. 
using a comma below for palatal consonants. One problem is that 
diacritics don't work well for all letters (e.g., above tall letters 
like "l" or below letters with descenders like "g"). Another is that 
words can become cluttered with diacritics and awkward to read when both 
consonants and vowels can have them. Examples from Jarda:

ģêła "against"
ğôļ "red"
ğŭģag "law"
pağŏ "baboon"

An older romanization used digraphs (and even trigraphs) to represent 
single sounds in Jarda. In some ways I like the old system better, but 
in other ways it's a little more awkward. Examples:

Thlar mrruvis khar zunthlom no citra byanag Oastena
Łaṛ mruvis xaṛ zunłôm nô ķitṛa bjanag Ostêna
"Celebration set tonight for Austin's bat colony"

Sha peandhlikhad, nyet Teakseosvoa zeunid kekhtiadma
Śa penḽixad, njêt Teksŏsvo zŭnid kêxtiadma
"Texas thirsts for hint of relief"

Javka zheam zlamada gerrkueneol karrvoe khrraksani
Ģavka źem zlamada gêrkünŏl karvö xraksani
"Raft keeps downed balloonist afloat in shark-infested sea"

Certainly the old system is easier to type! The third alternative, using 
new letters, is one that I've used only occasionally, as for example in 
Zharranh (which also uses some diacritics and one digraph). I use IPA 
letters for the retroflex sounds in Zharranh (ʈ ɳ ʂ ʐ ɭ), and to 
distinguish between /e/ and /ɛ/. An older Zharranh romanization used a 
number of digraphs for consonant sounds, and represented /e/ as "y" 
(with the justification that [ɨ] is one of the allophones of that 
phoneme in Zharranh). In a short-lived version of Minza, I used yogh (ȝ) 
for a phoneme with allophones [ʝ] and [ɣ]. But in general, using extra 
letters seems like more trouble than it's worth bothering with.