I am hereby ready and prepared to fulfill the positive commandment ... (Siddur).
Erev Succos is a day on which Jews busily prepare for the commandments of the festival - building, covering, and decorating the succah, acquiring an esrog (citron) and the other three species, and the other preparations that are common to all festive days in the Jewish calendar. The commandments themselves are not performed until the festival begins, but the preparations occupy people for many days beforehand.
One of the Chassidic masters said that Satan once brought serious accusations against the Jews before God, stating that they had committed grievous sins and should be punished. Although the archangel Michael countered with bundles of mitzvos that Jews had performed, Satan argued that the mitzvos were insufficient to outweigh the sins. There was great danger that the heavenly tribunal would decree a harsh judgment against the Jews.
The archangel Michael then argued, "True, the Jews may have sinned, but this was because they were unable to resist temptation, and these were not premeditated acts. No one has ever preceded a sinful act by declaring, `I am hereby ready and prepared to violate the prohibition written in the Torah.' It is only mitzvos that they perform with forethought and preparation, but never sins." This argument thwarted the evil plot of Satan.
We can see that as important as the performance of a mitzvah is, the effort in preparing for it may be even more important. On Erev Succos, when we adorn the succah, and we place the esrog in a beautiful container, and lovingly prepare for the festival, we show our dedication to the Divine mitzvos.