If you examine my realization of the melody and its orchestration, you may get some idea of how I went about it.
My realization of the melody, along with a recording
I started with bassoons in octaves, with a single clarinet (to smooth out the timbre) doubling the upper bassoon.
The second clarinet comes in at the unison for a few notes, at a discreet moment in the line, a few notes before the clarinets divide into octaves.
Notice that single flute coming in a note later? It's in a weak register, and will not sound out loud and clear as a new entry.
The second flute comes in ON the phrase, after a rest. However, this is also the spot I've chosen to begin my crescendo.
Notice the oboe entrance on the highpoint? Everyone is playing loudly, so their entrance will bring density more than a new timbre to the mix.
The sudden dynamic change in the last five measures required a drastic cut in orchestral density. However, I avoided cutting to a single timbre, prefering to keep one of each type of sound and blend them.
The very last notes are from two of the softest of the woodwinds. A very smooth timbral blend of clarinet and flute, both in registers where they can easily control the dynamic.