Depending on the “base” used for umeshu, you will find a wide variety of flavor profiles. For the novice, it may be good to start with a sweeter version, based on shochu. If you are a sake fan, obviously nihonshu-based umeshu will appeal.
Shochu: The most common base ingredient for making umeshu is shochu. These are usually heavy on the palate due to the high alcohol, and can be quite sweet. Each shochu imparts its personality: Rice will be on the clean side; imo (sweet potato) will have a bit of funk to it; and kokuto (black sugar) will have an inherent sweetness.
Brandy: Brandy-based umeshu are high in alcohol, and are similar to the shochu-based umeshu, but they tend to have a bit more complexity.
Awamori: The local shochu of Okinawa, awamori is notable for its earthiness. You will find umeshu based on it to have a bit of funk to it. Although awamori has the perception of being high in alcohol, though this brew is actually only around 13-14 percent alcohol.
Mirin: Mirin-based umeshu will be fat on the palate, and naturally sweet. Interestingly, the sweetness of this blend doesn’t come from added sugar, but from the mochi rice that mirin is made from.
Nihonshu: Umeshu made from nihonshu are quite light on the palate, and will have that characteristic sake aroma to it. Most umeshu from this group would make a nice complement to almost any meal.