When Ausra and I had traveled across Lithuania with numerous organ demonstrations, we found many village churches which housed beautiful yet small organs.
Sometimes local organists asked us to play some hymns during the service which preceded our demonstration.
Before doing that we would listen to the local organist register the hymns and were often amazed at how boring and one-sided their choices were.
John from Australia also has this challenge. The organ at his new church has 2 manuals and pedals - only 13 stops total - multiple 8' stops, a few 4' stops, 2-rank Mixture and Bourdon 16' in the pedals (plus the usual couplers, of course).
He wants to add variety in his hymn playing registration but fears that his playing would be too soft to lead congregational singing.
It doesn't have to be this way.
I had an experience in the US playing 3 stop one manual organ (Gedackt 8', Flute 4' and Principal 2' in the facade) on Saturday night services at our Grace Lutheran church chapel.
You wanna know what I did?
I counted how many color combinations can I have in this instrument.
And I used them all in my hymn playing:
8, 4, 2, 8/4, 8/2, 4/2, 8/4/2.
7 combinations! Not once was I criticized about the stop choices (the pastor didn't like my tempos sometimes but that's a story for another time).
Can you count how many combinations are there on a 13 stop organ?
I tried to do this on my "Creative Small Organ Hymn Playing Registration" training but I literally lost count.
Make your goal to find one more registration combination which nobody else uses.
Remember, there was a point in history when a mixture had more than 50 ranks! (and no possibility to separate them into different stops).