covering/ arranging a song

I want your input on this subject:
do you like only doing one instrument at a time, writing out it’s whole part
or
just going measure by measure doing all the instruments at one time?
What is easier?
Does having one instrument done first help with the rest?
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I personally think having a drum beat helps motivate me to continue on with a song. I generally go to the end of a verse or phrase with one instrument and then go back and do the others.

what is your covering/arranging process?

Usually start with the melody so I balance everything around that. Then the bass and drums next. Lastly any accompaniment like chords or ornamental stuff. If instrumentation changes or melody changes, I copy drums from previous section and mix tracks with that in mind to keep a consistent volume.

For me, I usually build around whichever instrument stands out most to me, which can vary between songs. In terms of progression, I tend to go one sheet at a time, making sure each one is fleshed out before starting a new sheet. I make it a note to make the important instruments more present than the accompaniment.