You can use any less expensive, commonplace capacitive stylus, but these do not offer screen pressure sensing nor palm/hand rejection.
For finer writing control, look at either disc-tipped capacitive stylii or something called a fine point, battery operated, so called “active” tipped stylii that use a tiny current from a battery source to simulate a capacitive finger touch in a smaller tip stylus.
Again NO palm rejection or screen pressure sensing, just a better finer point writing experience.
For either one of these, I recommend getting these from Adonit
They make s very good quality stylus across the board for all iOS devices.
httpshttps://www.adonit.net/jot/
https://www.adonit.net/jot/
https://www.adonit.net/dash/
For the palm/hand rejection issue, you CAN purchase a relatively inexpensive non-body electrical conducting writing/drawing glove that isolates your body’s electrical impulses when laying your palm or side of your hand onscreen.
Something like this, for example.
https://www.amazon.com/Professional-Anti-fouling- Drawing-Tablet-Graphic-Right-Ha nd-Left- Hand/dp/B017R8M2JY/ref=sr_1_1_sspa? ie=UTF8&qid=1543548123&sr=8-1-spons&k eywordshttps://www.adonit.net/jot/
If you wish a stylus that supports both screen pressure sensing and palm/hand rejection,
I strongly and honestly ONLY recommend the Adonit Pixel.
To get the most recent firmware for this device order directly from the Adonit website.
https://www.adonit.net/jot/pixel/
The compatible Notes apps tbat works with palm/hand rejection and screen pressure sensing.
Notability ( very good app, but palm rejection is noticeably improved using and inexpensive, non-body electrical conducting Lycra® material based drawing/writing glove. These can be found on Amazon.)
GoodNotes 4 ( NOT 5. Good Notes 5 dropped support for third party styluses. Good Notes 4 is still available )
NoteShelf 2
Zoom Notes
Quick Notes X Pro
That is it for Adonit Pixel compatible Notes-style apps.
All the apps above ARE the more popular notes-style apps anyways.
You CAN use other non-Adonit compatible notes apps with this stylus as you will get a finer writing experience, but with no palm rejection or screen pressure sensing, so a non-body electrical conducting drawing/writing glove would be necessary.