Start by booting up Alpine (see these instructions on how to do that)
When you Alpine is up and running, do the initial setup.
Enable Community Repository
Install basic desktop system and gnome packages. As of right now, these are in the testing repo.
This might take a few minutes depending on your network speed.
If you want to you can also install additional GNOME apps for a more complete GNOME experience with:
Setting up udev
You'll have to enable udev in order for GNOME to function properly.
Setting up Xorg
Even when using GNOME Wayland you'll still need a setup Xorg for XWayland.
Then install the driver matching to your card, e.g. if you have an Intel iGPU:
Also add the mesa-dri-swrast package:
Usually libinput is the best choice, as it's integrated best with GNOME and offers advanced functionality (e.g. palm rejection for touchpads).
Starting your desktop
Start GDM and login with your user. You need a user other than root for this to succeed, since GDM will refuse starting if no user accounts (meaning accounts with a UID >= 1000) are available.
Once you have verified that it actually works you can make gdm start up at boot:
Enabling terminal apps
If you want to use the gnome-terminal/other terminal applications you will need to install bash. If you want a typical bash setup also enable bash completion:
If you are unable to login, check /var/log/gdm/greeter.log, there may be output there from X to indicate failed modules, etc.
If logging in from GDM returns to logging screen, try
(bug report: #10953 sorry cannot link yet)