1. One who holds a Lulav upside down does not fulfill the Mitzvah.
2. We do not say that a Lulav is Muktzah for a woman on Yom Tov.
3. A minor may start to perform Mitzvos at an age when he is able to perform them in the required manner.
4. A minor is allowed perform Shechitah on animals.
5. In the times of the Beis ha'Mikdash, the Arba'as ha'Minim were usually held in the Beis ha'Mikdash on six of the seven days of Sukos.
A BIT MORE
1. This is because all of the four species must be held in the way that they grow.
2. Even though a woman is not obligated to fulfill the Mitzvah, it is not considered Muktzah for her since men are obligated to hold it. (This is in contrast to Shabbos, when the Lulav is considered Muktzah since no one can perform the Mitzvah then.) She therefore may handle the Lulav on Yom Tov (and fulfill the Mitzvah with it if she so desires).
3. For example, we give to a minor a Lulav once he knows how to wave it in the proper manner. Similarly, we give him Tefilin once he can abide by the laws of Tefilin.
4. However, he may do so only under the supervision of an adult.
5. However, if the first day of Sukos was on Shabbos, the Arba'as ha'Minim would be held all seven days, since in that situation they are held even on Shabbos.