Quick answer
Good counsel from a friend lands the way a fragrance does. The verse compares advice to something you experience rather than something you evaluate.
Read both lines
Ointment and incense were luxuries, and their effect is immediate, physical, and impossible to argue with. Putting counsel in that category says something specific: what a good friend gives you is not primarily information.
The NKJV footnotes "hearty counsel" as literally counsel of the soul, עֲצַת־נָפֶשׁ, which is the chapter's third nephesh in three verses. Counsel that comes from the whole person rather than from a stock of opinions. The verse sits deliberately after the wounds of verse 6: the same friendship that can cut can also do this, and the book treats both as the same gift. Notice also that the delight is doubled. The first line says ointment gladdens the heart and the second says the friend's sweetness gives delight, so the comparison is not that counsel is like a pleasure but that it belongs in the same category as one.
Related: Proverbs 27:6 · Proverbs 20:5 · Proverbs 15:23 · Proverbs 12:25
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.