Right hand advice

[Tiderider]

I'm sure this has been addressed many times on here, but please excuse starting another conversation. I've been beating on mandolins for around 20 years, I can play pretty well but I feel my right hand is just a mess at times.
Can you please recommend some good in depth sources for right hand technique. Thanks

[Bill McCall]

Sharon Gilchrist at Peghead Nation. Best I’ve seen, focused on the core fundamentals.

[lowtone2]

Andrew Collins has published a good video on right hand technique exercises.

[Marguerite]

With the right hand, you have:

Proper downstroke, where you hand rests on the string under the one you are playing, pick points (pointy part) upwards 45°

Proper alternate stroke. Pick is short (2-3mm sticking out) at 90° to strings and goes down up down up or, for exercise purpose and certain situations: up down up down. Movement comes from the wrist, underarm is not much involved, hand is floating. The whole idea is to learn the balance, hand, pick, etc.
This you can practise with repetitions, every note 3 or 4 or 5 times with easy flowing pieces without many string changes. then you can practise scales without repetitions and the same easy flowing pieces without repetition.

Alternate stroke also includes playing triplets in continous alternate stroke and having the accent once on downstroke, once on upstroke. That's what the 3x and 5x repetitions are for: to practise accent on the upstroke.

Tremolo. Very similar to alternate stroke with repetitions. Pick at 90° to strings, short (2-3mm sticking out) small movements, try to start in the middle (between two strings of a course) and always stay in touch with the strings. Movmenet comes from the wrist (not elbow), the hand is floating Find the balance for the pick (which you hold in a relaxed way, but it should stay where it is, at the beginning you will need to stop and adjust)
Practise slow flowing piece like "My way" "Moonlight serenade" or italian music (see "ballo liscio").
You can add tremolo over 2, 3 4 courses of strings, starting with small stretches and making them longer and longer. For tremolo over several strings, the pick has to stick out more, about 5mm to 1 cm. Hard to learn the balance between relaxed and keep pick in place. Adjustment needes often in the beginning.

Alternate stroke with many string changes. That's really hard, especially fast and coordinated. you can practise triads and triad studies, or also do exercises where you practise the string change all the time in all variations (change up in upstroke, in downstroke, change down in upstroke, in downstroke). If you practise in triples, constant string changes 2:1, you will comme across all variations. Example: your exercise is on D and A string, you pla DAADAA, in DUDUDUso you will have changes in all variations.
You can also practise string change patterns over 3 strings with a chord progression over 3 strings. Let's say (string names) DDAAEEED DDAAEEED (in constatnat DUDUDUDUDU), then you take a cadenza in C major or G major over 3 strings and just play the whole cadenza in this pattern, each chord two times.

Alternate stroke 2:1, analogue to downstroke only, pick rather long, at 45° pointing up, rest on next string between strokes. So you will only hit one string on the upstroke and obtain an heavy-light-effect, the downstroke is fuller, louder than the upstroke. Use when appropriate. There you will have triplets with patterns like DUD, DUD, for even DUU, DUU (if you like)

Crosspicking and arpeggio techniques: practis with chord sequences.

[Jairo Ramos]

Since you already play the mandolin, perhaps a book like The Complete Mandolinist by Marilynn Mair would be best...it's divided into several parts, and the main two are right-hand exercises and left-hand exercises...

[Ky Slim]

This video by David Benedict is really helpful for DUDU and string crossings