Fun tip for anyone who hasn't finished it yet.... I travelled to the Forgotton Grotto via the Starseed Teleporter, meaning I didn't have to max Handiness to get in there. Instead I just had to get 2 Fairy Dust to use the Teleporter after doing the rest of the quest tasks.
I am going to add to your fun tip for those who need as I am not sure what a Starseed Teleporter is. The best way I have found to raise handiness skill quickly is to have the Homey Lot trait (I think that is the name) that helps with handiness, cooking, etc. Go to BB to the activities and skills section, then creative section. I buy the big yellow basket of yarn for knitting, but I imagine any of the knitting kits will do. Sit your sim down and spam create friendship bracelets and handiness will max very quickly. Bonus tip, buy a bicycle and have your sim simply "ride it around" and you can max fitness quickly that way too.
