Whisky line up

If it were up to me I'd definitely have the HP 18 last in that line up. The lighter Glenmorangie first as you planned, and the sherried Macallan next. If you had any cask strength whiskies there, that might have thrown a spanner in the works - against a moderately peated whisky or a non-peated one at 60% ABV, which would you have first? It's a tough one - in the past, I've planned for a mid-flight break and put the cask strength at the end of the first "half" and finished with the peaty stuff in the second half.

Of course sometimes there just aren't enough synergies between whiskies to bother putting them in a single flight. In your case, with those three, I don't see an issue. The key though - don't worry about it too much and have fun! If something doesn't quite work out, oh well, there's always next time!

Don't worry about the order. It really doesn't make any difference in my opinion. The more you over-think it the more confusing it will be.

The way I conduct my tastings is get someone to put all the expressions in unmarked bottles. I put a number sticker on them to distinguish them.

That way when I taste I have no pre-conceived notions about the whisky. Once I'm done then I ask them to be revealed. I have been surprised on more than once occasion with the results.

I feel there is no real truth to ordering whiskies so that you have peaty last or sherry first. Your palate is strong enough and sensitive enough to withstand different flavor profiles in what ever order you serve it.

More importantly just enjoy the tasting - don't over think the order. Have fun!

@Maltmark, there is contrasting flavour here, but as whiskies (and whiskeys) go, this is a rather modest amount of contrast. I really don't think the order matters a great deal. If I were featuring these three whiskies, I would serve the Glenmorangie 18 first. Regarding the other two, I don't think it matters much which way you go. Yes, HP18 has the peat, but the Macallan 18 (1991) has to me an even more intense flavouring than does the HP18. The peat and smoke in HP18 are not for me at such a level as to be distracting to the Macalllan to follow. Flip a coin, or taste the Macallan 18 first. Then decide.

@Maltmark Order isn't important with those three. Just give your people a good time and write good jokes. I spend more time on that than what they are tasting.