Ideal lace making conditions include beverages of any kind, and a wee bit of distraction. Total silence is maddening, so a little noise is good, and makes that lace magic happen.
I enjoy working on 'easy' lace patterns at SnB...you know: k2tog, yo,k,yo,ssk,k, repeat. I can actually chat and knit at the same time. However, if it's a pattern that actually requires me thinking about it (which is uhmm...most of them), I tend to have the television on, and follow the chart. Hopefully it's on something I taped, so that I can rewind the tape if necessary (no TiVo here).
And ideal would be no small children tugging on me whilst I'm knitting lace (that's not about to happen, so most lace knitting occurs after bedtime).