To install, just simply extract this archive's contents you want, inside the Mods folder.

For example if you want my MobilePhone reskins and backgrounds, then
extract the contents of my "MobilePhone" folder to your "Stardew Valley\Mods\MobilePhone" directory and replace when asked.

Like wise, if you want my CustomReminders icons, then 
extract the contents of my "CustomReminders" folder to your "Stardew Valley\Mods\CustomReminders" directory and replace.

Enjoy!