Involve members in giving programs or reports. Giving your first talk at an astronomy club meeting is a rite of passage for those concerned with expanding the number of people interested in astronomy. Cultivate a group of accomplished speakers in the club and use them. Don't be afraid to ask as their leader. Encourage members to try it.
Members are often the best source of introduction-level presentations.
Shy members often do a great job because they will take the time to prepare well. Eccentric members often do a great job because their unusual viewpoint may cause us to look at something familiar in a new or humorous way. Less experienced speakers may need a little extra support, guidance, and protection but it is usually a sound investment. Encourage presenters to prepare and distribute a simple handout containing the details of their message. People love to get a freebie and it allows the audience to listen to the speaker rather than take notes.