“The best preparation for tomorrow is doing your best today.”
Source: P.S. I Love You
Harriett Jackson Brown Jr. is an American author best known for his inspirational book, Life's Little Instruction Book, which was a New York Times bestseller . Its sequel Life's Little Instruction Book: Volume 2 also made it to the same best seller list in 1993. Wikipedia

“The best preparation for tomorrow is doing your best today.”
Source: P.S. I Love You
“Think big thoughts but relish small pleasures.”
Source: Life's Little Instruction Book
“Life is slippery. We all need a loving hand to hold onto.”
Source: Life's Little Instruction Book: 511 Suggestions, Observations, and Reminders on How to Live a Happy and Rewarding Life
“Judge your success by the degree that you're enjoying peace, health, and love.”
Source: Life's Instructions For Wisdom, Success, And Happiness
Source: Life's Little Instruction Book: 511 Suggestions, Observations, and Reminders on How to Live a Happy and Rewarding Life
“Don't forget, a person's greatest emotional need is to feel appreciated.”
Source: Life's Little Instruction Book: 511 Suggestions, Observations, and Reminders on How to Live a Happy and Rewarding Life
“I've learned…. That being kind is more important than being right.”
Source: Live and Learn and Pass It On, Volume II: People Ages 5 to 95 Share What They've Discovered About Life, Love, and Other Good Stuff
“Never give up on anybody. Miracles happen everyday.”
Source: Life's Little Instruction Book: 511 Suggestions, Observations, and Reminders on How to Live a Happy and Rewarding Life
“Be tough minded but tenderhearted.”
Source: Life's Little Instruction Book: 511 Suggestions, Observations, and Reminders on How to Live a Happy and Rewarding Life
“1425: When you really like someone, tell them. Sometimes you only get one chance.”
Source: The Complete Life's Little Instruction Book
“Approach love and cooking with reckless abandon”
Source: Life's Little Instruction Book
“Tape record your parents' laughter”
Source: Life's Little Instruction Book: 511 Suggestions, Observations, and Reminders on How to Live a Happy and Rewarding Life
Source: Life's Little Instruction Book: 511 Suggestions, Observations, and Reminders on How to Live a Happy and Rewarding Life
“Seek opportunity, not security. A boat in the harbor is safe, but in time its bottom will rot out.”
Source: The Complete Life's Little Instruction Book