There are two "more sophisticated ways". The following directions are for Finale 2003:1. Options menu - Pickup Measure...
This solution uses the Mirror Tool to insert "placeholders" before the pickup notes, thus pushing the pickup notes to the right.
2. Time Signature Tool. Double-click the first measure. The dialog box "Time Signature" appears.
In the pane "Measure Region", click the upper radio button (Measure 1 through 1).
Click the button "More Choices", and click the option "Use a Different Time Signature for Display". With this option you can make measure 1 display the time signature of the following measures (e. g. 4/4), even if measure 1's real time signature is less (e. g. 1/8).
In the upper part of the dialog box, set the time signature for the pickup. If you want a complex beaming pattern (e. g. 3/8 beamed as 1+2 eighths) click the button "Composite...", and define a composite time signature (1/8 + 1/4 or 1+2 over 8).
Both these "more sophisticated ways" work well.
Solution 1, the "placeholder" solution, has a small limitation, due to a Mass Edit Tool conflict (bug) between placeholders and tuplets:
If you have a tuplet in the pickup, you have to enter the tuplet notes manually in each staff. You can't copy them with the Mass Edit Tool.
Solution 2, the "time signature" solution, has no limitations.
Peter