Wisdom is sweet.
v.20 Meditate. Here the proverb tells us the you will find good if you give thought to the word (of God). I understand this as meditation (and heeding the instruction). The second verset states that blessings will be upon those who fear the Lord. The fear of the Lord is he beginning of wisdom. It seems to say that you will find your way prosperous if you live a life rightly before God. Amen.
v.21 Wise speech. Here the focus is on the reputation on the one who has a habit of speaking wisely. He (or she) will be known as discerning and his words will be persuasive. His words are sweet or pleasant (because they are well received).
v.22 Good sense. To him who has it, good sense is a fountain of life. This good sense is obtained by fearing God and thereby gaining wisdom. On the other hand the instruction of fools (stupid people, Longman, 335) is just the opposite (folly or stupidity) and brings punishment (for sin).
v.23 Judicious speech. Here the heart of the wise makes his speech judicious and persuasive. The wise heart “guides” his speech. Your words are a reflection of what’s in your heart. See also v.21 above.
v.24 Gracious words. Gracious words are sweet to the soul like honey to the mouth and bring healing to the old bones (your core person).

Read Proverbs 16:20-24