Completely flipping your classroom with videos, clicker questions, etc. is a lot of work. One way to make it happen is to do it in stages. It’s better to do a little bit than nothing at all.
The alarm clock approach
If you feel you can’t spare five minutes for a clicker question because you are always hopelessly behind in the lectures, there may be something seriously wrong with the way you teach.
An experiment: is the lecture necessary?
It’s hard to write good clicker questions. Be prepared to replace questions that are too easy or too hard the following year.
Reading quizzes. You should give students a reading quiz before every lecture, in which you ask clicker questions about new material. The reading quiz shouldn’t consist of more than seven questions that are easy to answer (if you have done the reading or watched the video). I often use true/false questions. It usually takes me 15-20 minutes to write this kind of quiz.
Video lectures. The optimum length for a video is about seven minutes. If you already have lecture notes or PowerPoint slides and are comfortable with the recording software you use, then making a seven-minute video takes about 15-30 minutes depending on the amount of editing you do. This does not include the upload to Youtube, which can take up to 30 minutes depending on internet speeds, but you can do other things during that time.
Recording live lectures
In either case you should edit the recording into shorter videos no longer than 10 minutes. It is just a boring and off-putting to watch a 45-minute lecture online as it is live. If possible, insert a question at the end of each video to activate the students.
Other universities have recorded lectures and put them online, so you might be able to find what you need just by googling or searching on Youtube. Notice that if you only want the students to see part of a video you can specify the start time in the Youtube link. You can also use the site eduCanon to add questions to the videos to make it more interactive.