A good mug as you say op! My dd played a blinder a few birthdays ago for me getting me a mug based on a favourite film BUT it's a decent size without being too big, it's not too heavy AND I CAN GET ALL 4 FINGERS IN THE HANDLE
I hate getting mugs that are awkward to hold/pick up
Extra long charger leads - in different colours for different tech! Makes life so much easier
As does the lencent 4 port usb plug adapter I got based on a recommendation on here!
So so useful and when dd was going on her first holiday without me I got her one. She was a bit  ... then was ms popular with her friends on that holiday!
Also the omeril led head torch also recommended on here. I use it for crafting as my eyesight isn't what it was, but soon after I got it we had a power cut and it was soooo useful! Angles and has different light options, I'm thinking also very handy for parents of young dc and carers
Ear loops for my airpods - they will not stay in my ears so I got these ear loop things - game changer
I always have a fountain pen, ballpoints are fine for quick notes but for really pleasurable writing always a fountain pen - @hilariousnamehere I favour teal and forest green myself
Nice smelling candles/tea lights
Nice perfume that doesn't make my skin go angry!