We will refer to the practices you mention and a few others (although this list is not exhaustive), categorizing them according to our appraisal of the chumrot (stringency). The most basic unanimous requirement (i.e., not a chumra) is that mishlo’ach manot must include two food portions, as indicated by the plural manot.[1]

Proper to Be Careful (strong opinions require them)

Respectable quality/quantity – The gemara[2] tells of two Amoraim, one who sent simple foods and another who sent sharp spices, and of a colleague who implied that this was inappropriate. Many explain that mishlo’ach manot are supposed to foster warm relations and/or that they are for seudat Purim use.[3] Therefore, it is not surprising that poskim maintain that the manot should have some importance[4] and perhaps that the affluence of the giver and/or of the recipient affects what is considered sufficient.[5] However, the opinions[6] that one person’s mishlo’ach manot should suffice for some level of an entire independent meal (as opposed to simply being a nice enhancement to a meal) are fewer and weaker.
Ready to be eaten – The Magen Avraham[7] requires that if one gives meat as mishlo’ach manot, it must be given already cooked. The logic behind this is that raw food misses the mark, as the recipient cannot enjoy it without effort. The Mishna Berura[8] cites this as the primary ruling, while noting that there are also distinguished lenient opinions. (Some mistakenly understand that one must always give cooked food, but in truth, this is an issue only for food that is inedible raw.) While important poskim are lenient,[9] this is an easily-followed and logical stringency that most people should adopt.

One May Want to be Careful (minority strict opinions with a measure of weight)

Drinks do not count – Some claim[10] that manot refer to solid food, not drinks. This is based on a minority text of a Talmudic story about a complaint of insufficient manot, which identifies the problem as a drink having been given instead of a second food item. However, an explicit gemara[11] tells of a rabbi who sent a nice portion of meat and a barrel of wine, indicating that drinks are fine.[12] The Magen Avraham[13] and Mishna Berura[14] rule that drinks do count.
Kedushat shvi’it – It is forbidden to pay debts by giving fruit that has kedushat shvi’it.[15][16] Some say that fulfilling one’s religious obligation to give mishlo’ach manot is like paying a debt, and it is therefore prohibited to fulfill the mitzva by using shvi’it fruit. (This applies only to the first valid mishlo’ach manot that one gives that year, through which he fulfills his obligation).[17] Others say that using shvi’it fruit is prohibited specifically when one gives mishlo’ach manot as reciprocation for having received something from someone, as the need to reciprocate is like a debt.[18] However, many are lenient,[19] including, apparently, our mentor, Rav Shaul Yisraeli.[20]
Separate utensils – The Ben Ish Chai[21] says that whatever is in one utensil counts as only one portion. This opinion is difficult to maintain concerning foods that are by their nature unrelated (as opposed to foods such as assorted candies in a container[22]). However, probably partially in deference to the Ben Ish Chai’s stature, several Sephardic poskim endorse this stringency l’chatchila.[23]

Unwarranted Stringency

Foods of different berachot – The two manot must indeed be unique units. Many poskim say not to suffice with one food that is merely separated into two portions (even if each is large).[24] However, the idea that foods’ berachot are an indicator of being separate is contradicted by many prominent sources and is, in fact, illogical; note that meat and juice share a beracha, whereas different types of potato chips may not.

These stringencies are meant to ensure that one fulfills the formal mitzva; they are not always indicative of the mitzva’s goals. Therefore, as long as you give “halachically mehudar” mishlo’ach manot to one person, the idea of giving to many people[25] to cultivate friendships and make people happy on Purim can be done in any way that enhances the Purim spirit. Do not let chumrot stifle your energy or creativity!