One must treat him/herself as one would expect others to treat you. Essentially, this means good control, understanding and discipline. "Spoiling" a kid or yourself doesn't get anywhere. Reward for achieving some production or personal goal is different from constantly luxuriating because one "can afford it".
As well, treat yourself with compassion. Because you have a bad day occasionally, just vent in some private moment and get over it. Then analyze what didn't go right or isn't working out according to your own vision of how things should be, then plan how to get from that point to where you want to be within the resources you have or can readily acquire.
This may require that you allocate some time daily into review of goals and plans. Some put meditation into this spot, some take quiet walks in the woods or exercise.
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Another point is using various methods to control your own attitudes. When one finds anger dominating one's life, you can either vent (as above) or simply take some time to slow down your breathing, relax your facial muscles and force a smile. Keep this up and if not downright cheerful, you'll become calmer and able to think more clearly.
This would also bring up a possible line of research into Eastern philosophies, particularly those which encouraged physical discipline, such as the martial arts. One would eventually achieve a complete quiessant attitude such that the external environment would be able to be handled without stress.
Bottom line would be a philosophic base which was itself a stable solution to all possible life situations.