Here is a homebrew gnome, based largely on the 3rd Edition version. Alternatively I could see a bonus to Intelligence or Charisma.
TraitsAs a gnome, you have all the following racial traits.
Size: Small.
Speed: 25 feet.
Low-Light Vision: If there is no light within 30 feet of you, you treat shadows in that radius as normal light, and you treat darkness in that radius as shadows.
Gnome Weapon Training: When you attack with a pick with which you have proficiency, the damage die for that weapon increases by one step: from d6 to d8, or d8 to d10.
Illusion Mastery: You have advantage on checks and saving throws made to detect and resist illusion spells.
Languages:You can speak, read, and write Common and Gnome.
Ability Score Adjustment: Your starting Constitution increases by 1.
Cantrip: You know and cast the minor spells dancing lights and ghost sound.
Dancing Lights
Minor illusion
You conjure one to four glowing spheres of light, or a faintly glowing humanoid shape.
Effect: You create one to four lights that resemble lanterns or torches (and radiate light as such), glowing spheres of light (that look like will-o’-wisps), or one faintly glowing, vaguely humanoid shape within 50 feet. The lights must stay within a 10-foot-radius area in relation to each other, but otherwise can move as you desire. You can move then 50 feet as an action, but wink out if they move further than 50 feet from you. The spell lasts for 1 minute or until you cast it again.
Awful Good Games 