They become indepenent so fast, why promote it?

The best way to have them play alone is to sit with them and play with the toy. Then the next time sit and play, then stop playing. Then next time as they play you do something else near them. Eventually with no upsets and no tears they'll play alone for a few hours.

WRT walking holding hands, I had two months of this, then I put DS in his cot, helped him stand holding onto the cot and showed him how to cruise. Best thing I ever did! He was walking independently within two weeks.