The simple past, as in "I saw her" or "Did you see her?", generally implies a specific time, or inside a specific time-range that ends before the present. For example, I might say, "I was looking for her all of yesterday, but I didn't see her." This means that I didn't see her yesterday — but it doesn't say anything about whether I've seen her today. The following sentence could easily be, "So I guess she must have left town; I don't know if I'll ever see her again", or it could just as easily be, "But then I ran into her five times today, when it was already too late to invite her."
By contrast, the present perfect, as in "I've seen her" or "Have you seen her?", implies that the time-range of interest ends at the present. For example, one might say "I've been looking for her all day, but I haven't seen her."
It is possible to have two sentences that are identical except for this distinction, in which case the verb form conveys an important nuance of meaning. "I didn't see her today" implies that "today" has finished in some way — perhaps she is a coworker, and what I mean is that I didn't see her at work today, even if it's possible that I might run into her at the grocery store in the evening — whereas "I haven't seen her today" implies that there's still a chance that I will see her later today.
In your example, however, I would say that only "I'm looking for Paula. Have you seen her?" is acceptable. I cannot think of a context where "I'm looking for Paula. Did you see her?" would make sense. "Did you see her?" implies that you are referring to some specific past time or some specific past time-range; but since it doesn't explicitly indicate the time-range, that must be inferred from context. The problem is that the previous sentence, "I'm looking for Paula", implies that the time-range of interest is now, and the "did" version must end before now, so it's not compatible. As a result, saying "I'm looking for Paula. Did you see her?" makes about as much sense as "I'm looking for her. Have you seen him?" — the second part must be referring back to something, but it clearly can't be referring back to the first part, so the whole thing comes out sounding like gibberish.
In sentence 1, both verbs, make and wake, are in the present tense, but in English the tense (i.e., the verb form) doesn't always refer to the obvious part of the timeline. Here you might reasonably expect the current time, but this usage talks about a rule that's true in general. You should have made your bed when you were a kid, you should be making it now, and you should make it for the foreseeable future. (At all times, after you're awake, of course.) This is sometimes called the enduring present tense.
In sentence 2, the normative aspect (the "ought to", the should) still expresses the general rule, but woke (the past tense of wake) conflicts with that rule since woke is confined to past action. This makes the sentence ungrammatical. If you want to keep the waking in the past, then you have to transpose the bedmaking to the past as well:
2a. You should have made your bed after you woke up.
Of course, that's not a general admonition; it's about just that time after you woke up.
So why does 3 work, with the waking in the present perfect (have woken)? The clue is in the name. The "perfect" means that the verb speaks about completed action, and the "present" means that the action takes places at any time up to the present or that it affects the present. That necessary reference to the present is missing in the simple past in sentence 2.
Best Answer
When the runner finishes the race, the runner crosses the finish line. When the runner has finished the race, the runner is across the finish line.
In American football, the player scores a touchdown when any part of the ball breaks the (imaginary) plane of the goal-line (the plane is perpendicular to the playing surface). The player has scored a touchdown when that action is deemed to have taken place.
The difference is merely in how the event or action is understood. The facts "on the ground" are the same. We can understand the action as one in which a boundary is crossed or one in which a boundary has been crossed. It simply involves a shift of a virtual vantage point.