Dorene, your hubby should be ashamed of himself for not answering this himself
I can't call myself an expert by any means, at best a hobbyist, but I can tell you what I look for personally. In very young ports (such as the 2003s Roy recently tasted) I would be looking for things such as
The nose. What does it smell like? Does it offer interesting and attractive aromas, like different fruits, herbs, spices, forest, rain, woods, earthy notes, etc., etc.? Wines that are not so good can present aromas of unattractive compounds, like ethyl acetate (nail polish remover), oxidized components that smell old or rancid, etc.
Intensity and concentration of flavors. In general, Ports with greater concentration are judged "better," perhaps because that is an indication of potential ageability - besides the fact that they just taste better.
Level of ripeness/sweetness. Everyone has different preferences here, some like sweeter riper wines, some like them less sweet. Personally, I prefer Ports on the less-sweet end of the spectrum, with more brooding baritone flavors (as opposed to what I call higher-toned soprano flavors).
Depth, complexity, and interest of flavors. As with any wine, different Ports offer different mixtures of flavors. Some are relatively one-dimensional, straightforward wines, which might remind you of of simple grape juice. The better wines, IMO, offer a range of interesting flavors, which might include darker fruits (e.g., plums, prunes, olives, blackberries, boysenberries, blueberries, etc.), herbs and spices (such as anise, pepper, cinnamon, cloves, sage, lavendar, etc.), and lots of other descriptors. The best wines combine interesting flavors with multi-layered complexities: different layers of flavors that present themselves in succession, like waves coming onto the shore.
Acid and Tannic structure. A good young Port needs a strong tannic backbone to allow it to age for decades, and sufficient acidity to help balance all the other components. Too much acidity can be distracting, like a Margarita with the lime flavors out of balance with the sweetness. Too little acidity makes a wine taste bland. Tannins gradually fade in a wine by chemically polymerizing, which makes them appear less obtrusive (and often results in the sediment that you find in the bottom and sides of an older bottle). You're looking for enough tannins so that when the wine is in its ripe old age, there are just enough to provide good balance to the fruit and other flavors. It's a little like opening a Coke. The first gulp can be almost overwhelming from the high amount of carbonation. A little later, it is easy and pleasant to drink, but leave it too long (analogy to leaving the wine to long and letting the tannins drop out completely) and you have a flat, uninteresting drink that just tastes insipid. Tannins also have varying characteristics that appeal to different people. You 'll notice some that seem "chalky," which seem to appear particularly on the finish of some wines; others might be drying, as if the inside of your mouth was just hit by a hair dryer; or some are mouth-puckering, like that sensation you get eating a lemon. I tend to look for what I call "balanced" tannins, which make me feel their presence, but don't poke out strongly in any of the ways I just described.
The finish. A great wine doesn't let you forget it for a while after it's no longer in your mouth. Bad wines can do this as well, with bitterness, too much sweetness, funny or unappealing aftertastes, etc. A good wine will carry forward it's good qualities with its core flavors continuing to echo in your mouth for many seconds after you've finished it - sometimes as long as a minute or two.
Now, as for how you guess which Port is in which bag? In my case, I put a little secret mark on any bagged wines I bring, which allows me to "amaze my friends" with my incredible palate memory
In the absence of cheating, there is really no substitute for experience: having tasted a wine before, preferably several times; having tasted multiple vintages of a particular wine, so that you begin to develop a sense of the typical flavors of the vineyard, and style of winemaking of the producer.
My wife is probably in the same position you are. She likes wine, and enjoys the wine activities we do, but doesn't have much interest in delving into it the way I do. But give here a glass of bad wine, and she hands it back to me; and give here a glass of good wine, and she spots it instantly - in which case I probably won't get the glass back. The point being, you probably know a lot more than you think you do