Could some of the experts give their opinions on the best method of actioning stop loss sell orders.

In particular does one;

a. wait until the close
b. work on the closing price as triggering the stop loss or any of the intra day trades
c. place the sell order "at market" for the following day or at the end of day offer price.

I trade on line and generally monitor my watch list twice a day, about 1 pm and then after the close.

Thanks in advance.