Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls.
(Now the man Moses was very meek, above all the men which were upon the face of the earth.)
What made them meek?
An intimate personal relationship with God.
And submission to God's will.
THE key (not 'a' key) to a meek and quite spirit is spending time with God. If we give Him the start of the day, He will work things out for all else to be done and/or give us the strength to endure the day with a little less sleep. This does not mean my day will be without trouble, but I will better be able to handle those troubles.