A financially responsible but substantial reduction for early registration helps in estimating the final attendance. Too small a reduction will not be used as there is always a chance that a participant must cancel. Early registrations are a big help in predicting tutorial attendance, too. If there are industrial financial sponsors, the organizers might want to offer them a reduction in registration fees. One successful recipe was offering five registrations for the price of four.
Credit cards are a convenient means of paying registration costs.
Note that the credit card companies will keep some 3 to 5 percent of the funds collected in this way. Students are often allowed to register at a reduced cost. Review any feedback or questionnaires from previous conferences in the series. Design, get approval, print and distribute call for papers. Many journals publish meeting announcements in their conference calendars.