There are many crystals for grounding but the three main ones I like are: Black Tourmaline, Haematite, Smokey Quartz. Together they are wonderful or you can use them separately. The choice is yours.
1) Take whatever grounding crystal you want and place it on the ground outside then with barefeet walk on the crystal or stand on the crystal ... this is great for jetlag too as this exercise actually alignes your energy with Mother Earth for tyour current time zone.
2) Walk around barefoot on Mother Earth.
3) Lay down on the ground on your belly with your knees and elbows bent, rest your chin in your hands and cross and uncross your legs three or more times breathing deeply.
4) Hug a tree and enjoy the energy transfer.
5) Go out and walk in nature: a forest, walking in the bush, beside a waterfall, walk beside the ocean, etc.
For really great information on crystals and their uses check out www.hibiscusmooncrystalacademy.com ... I hope this helps.