Q. We just finished learning Maseches Kesuvos in our Daf Hayomi shiur. What is the best way to end the Maseches. Should one learn it completely until the end and then have to do the Siyum Seuda and celebrate on that very occasion.
Or is it better as many do, to leave out the last paragraph or some lines of the last page, until one is ready and prepared to make and use the Siyum Seuda in the right propitious occasion and setting?
A. Horav Shlomo Miller’s Shlit’a opinion is that it is better to finish and bring the learning to completion immediately.

Since we always say that the one who starts a mitzva should bring it to completion.

Yet, the above does not stop one from repeating the ending at the right propitious occasion and setting, and then doing the Seuda. This is similar to the ending of one of the Chumashim of the Torah reading on Shabbos and saying Chazak, and then repeating it for the Maftir reading.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit’a.