Do you have some tips/tricks for training to sing above F4 in m1?
The most common excercise is really that top-down excercise. You go into hooty falsetto on the vowel OO on a high note (at least G4, better higher), then slide it down as low as you can.
Then you try to keep that vocal tract posture and make a new onset on an AH vowel in your chest voice but you try to keep the position roughly intact that the falsetto created when you brought it down.
That AH should then transition out of chest voice at a point that is suitable for your voice (usually between D4 and F4) but it should stay modal voice. On thing you have to keep attention on is to keep singing "forward" and not up when you go up on that AH. Try to fixate a window or something in your room and sing out of that window.
Another thing that works well for me is to train on the vowel /OE/. This vowel has a natural posture that is similar to the falsetto-down posture. The vowel /OE/ sounds like the "e" in the englisch word "herb" or like the "u" in the englisch word "murder". But also here it is important to "project", to sing forward into the distance.
Great answer by Rob. Its really just what you describe, Khassera. It's starting on a "no configuration" setting, just to release every configuration that you might unconsciously have set up in your vocal tract and that might disturb your following configuration.