Just as is the case in “real world”? poker, all video poker players have different ways of handling the kicker card. Some players hold on to it for as long as is reasonably possible, while other video poker players cannot seem to get rid of them soon enough. All methods of course have their own strengths and weaknesses, and there really is no best way to deal with them.
In the Double-Double Bonus Poker or DDBP variation of video poker, this is a common enough subject of debate. By most expert video poker players estimation, the best thing to do with the kicker cards is to get rid of them quickly and try to get one more shot at the fourth ace. Of course this rule only applies if you already have three aces and one kicker card.
A notable exception to this rule is in the Triple Double Bonus variation of video poker where it may be beneficial to hold on to the kicker card for a while, at least until you have had two shots at the fourth ace. Of course some training and experience in building an effective video poker strategy would help in this situation, in order to get better chances at a good game return.