If I'm planning a commercial shoot in advance, a small amount of alcohol often helps. For the actual shoot, no. For post, it's almost essential to have a glass of wine or beer, but not too much. For personal photography, a drink can help, but too many and forget it. For my business consultancy, the data gathering has to be done with a clear head, but a drink or two can help me make sense of it and see solutions. So for me, it's a fairly narrow gap where creativity is enhanced.