The wise king Solomon’s advice on preaching:

Ecc 12:10
“the preacher sought”: a good preacher studies how to put across his teaching in an acceptable and memorable manner.

“acceptable words”: to speak in a manner which will be well received by his hearers. This does not mean pleasing words, which will not upset people, but it is expanded and explained in Ecc 12:11.

Ecc 12:11
“goads”: Heb: dorbown. The words of the wise provoke to action.

“nails fastened”: the words of the wise are as goads, which stick in the memory. These words are fastened because they are received and accepted by the hearer, and thus are acceptable words Ecc 12:10, like the seed received into good ground Mat 13:23.

“the masters”: Heb: ba’al, the same word as Baal, the heathen deity, which has the root meaning of being a master because of one’s masterly work, being a master craftsman.

“of assemblies”: Heb: ’asuppah ‘a collection of (learned) men’. It is a masterly work to teach assemblies, requiring the knowledge of words, one’s subject and one’s audience to be able to fasten acceptable words in the minds of one’s hearers. The wise, through study Ecc 12:10, attain this knowledge to fasten acceptable words in the minds of their hearers. People will not act if they do not remember.

Application: preachers are to be wise and to study how their words will stick in the memory of their hearers in such a way as to provoke them to action. Words and hearing without action are like faith without works Jam 2:20,26. Paul joins them when he speaks about the “work of faith” and “labour of love” 1Th 1:3. Repentance is a change of mind that leads to action, and it is not complete without action. Individual Christians and congregations need to repent and believe Christ’s great commission to “Go” and “make disciples of all ethnic groups” Mat 28:19. In order to do so, each believer must seek spiritual wisdom and learn how to fasten their words in their hearers’ memories as goads to action. Preachers should review their sermon to see if there is a memorable matter that will stick in people’s memories, particularly which will goad them to action. Think of something which will recur in their lives, and associate it with some Gospel truth or action. When these events recur, they will act like reminders. There are many examples that can be given but, to promote a particularly rare subject in Christian living, I will use fasting. The preacher could teach the congregation that their hunger pangs will remind them periodically that it is time to pray, and prayer, in turn, will take your mind away from the desire to eat – helping both body and soul to keep ‘in trim’ – “exercise yourself to godliness” 1Tim 4:7. A preacher could take time to invite the drunkard to concentrate his mind on the colour of his alcoholic drink Pro 23:31, and then accompany it with the warning that it will bite like a serpent Pro 23:32. Thereafter, when he is looking into his alcoholic beverage, the warning will come up into his mind.

Source:

A Commentary on the Holy Bible, Donald M. Boyd.

13 Jun 2019: Charles Haddon Spurgeon, ‘the prince of preachers’, illustrates this teaching skill very well with his use of drinking fountains in his Morning & Evening at 13th June on Rev 22:17 to illustrate the freeness of the Gospel, its availability to all that pass by, and how some will ignore it and not use it.