please do this to install gnome tweak tool.
open terminal (ctrl + alt + T)
sudo apt install gnome-tweak-toolnext, install adapta ( An adaptive Gtk+ theme based on Material Design Guidelines )
sudo apt-add-repository ppa:tista/adapta -y sudo apt update sudo apt install adapta-gtk-themeInstall Numix icon theme
sudo add-apt-repository ppa:numix/ppa sudo apt-get update sudo apt-get install numix-icon-theme
Now, activate adapta theme and numix icon through tweak tool
here a few gnome shell extensions will make it better look and feel
dash to dock to customize your dock, transparent top bar to make adapta top bar transparent and Hide top bar to maximize your workspace.
- install dash to dock gnome shell extention, and customize it.
settingsDash to dock
- install Transparent top bar extention.
settingsTransparent top bar
- install Hide top bar gnome shell extention.
settingsHide top bar
done, Enjoy Look and feel Google material design on ubuntu.