Lifts are a discipline in itself. I have serious doubts that they can be tought strictly with video tapes. I have been trained in lifts and aerials, and this is what I have learned:
1. Strength is not essential but helpful. It is not the male who initiates the lift; rather, the female partner jumps so gracefully that the spectator is left with the impression that the male uses strength.
2. For reasons of stability, a rule of thumb saids that there ought to be a minimum of 40 Lbs difference between male and felale partner.
3. Timing is of essence. If when the female partner initiates a lift with a jump, the male partner is not synchronized with his lifting assistance, one of two things can happen: (a) The lady partner jumps earlier, and when the male partner offers lifting assistance, she is descending due to gravity and appears to weigh a lot more than she does (b)If the female partner is late, then the male partner has to litterally lift the true weight of his lady partner.
4. Once the lady partner reaches the highest point she is supposed to, it is the male's bone structure that supports the female's weight, not the strength of his muscles.
5. The lady's posture is extremely critical. Her posture depends on the figure. However, a general guideline applies: Whatever makes her body appealing to the human eye is usually technically correct. For example: the lady's arch of her back and neck accentuates the beauty of her figure, and simultaneously distributes her weight in such a manner that she can litterally give her partner the impression that he is lifting a feather. Conversely, a bad posture of hers usually gives to her male partner the impression he is lifting a heavy sack of potatoes.
6. My experience is that regular training is required to maintain the timing between partners. For example, 3 hours of training per week, just for lifts.
7. Never attempt lifts without supporting helpers. Their role is to secure the female partner until the lift becomes so familiar that she feels comfortable.
I hope these pointers help. Cheers!