There are two types of items that ultimately grant AP: ones that do so directly, like AP potions and Mojitos, and ones that do so indirectly by granting experience, like experience fruit, or archeological artifacts. There's no "best practises" for consuming items that directly grant AP since there are no restrictions on when you can do so. So, you just go ahead and consume them; easy-peasy.
Items that grant experience, so that they indirectly grant AP, are a different matter. These come in two varieties: ones that give a fixed amount, like archeological artifacts, and ones that give a fixed rate, based on the current amount of accumulated experience. Here, one must keep in mind that there are limits to the amount of experience levels that can be gained per rebirth, and so consuming something that grants more experience than can be obtained results in the efficiency of that particular item consumed being curtailed. In short, as you get near the limit of experience, for the rebirth, one has to eventually either accept that the last item consumed will be done so less efficiently or will not be done at all, and that any further experienced gained will have to be done "the hard way". The limits, per rebirth, are: 200 levels of ordinary experience, and 50 levels of exploration experience.
There are two further considerations to make for consuming both varieties of items. Since both come in different amounts of either raw experience gained or rate of gained experience, one has to decide if the order in which they are consumed matters and if so what should that order be. The second consideration is whether when, during a particular rebirth, they are consumed matters and if so when that is: right after rebirth, right before, somewhen else.
Fixed amount experience items become increasingly less efficient as more experience is gained. As such these items should be consumed immediately after rebirth, largest to smallest. This maximizes the efficiency of the larger ones. As experience is gained these items quickly lose efficiency, as such one has to seriously consider if they can spare storage space to hold these items in inventory over the course of several rebirths in order to gain the most use from them. Decide how many rebirths you can hold them in storage, calculate what the total experience gain will be, and consume an equal lot of them, from an experience gained point of view, for each individual rebirth that you will hold them.
Fixed rate experience items become increasingly more efficient as more experience is gained. As such these items should be consumed immediately before rebirth, smallest to largest. This maximizes the efficiency of the larger ones. Since these items become more efficient with experience one is free to consume as many as they want but keeping the upper limits in mind.
