help with trills

[Saturn]

Any tips on how I can practice the trills at the end of the first movement cadenza of beethoven's 3rd concerto?

There's two trills on the right hand (simultaneously), D-Eb and G-Ab.  I tried practicing the two separately, but when I put them together, I can't trill very quickly.

[JK]

What fingering are you doing? The fingering that I would do would be 1-5,2-4 etc. This for me personally is the best fingering for trills in thirds and double trills.

[Saturn]

I was using the fingering 1-2 4-5.  1-2 5-4 feels strange to my fingers, but I'll try it and see if it works better.  Thanks.