"all you need is love" is a slight exaggeration, but it's true that loving and being loved is a large component of happiness.
It appears to be combination of:
"don't forget to stop and smell the roses", "life's a journey", etc. In my experience, it is actually possible to learn to enjoy things that you didn't use to enjoy (I'm not talking about making something unpleasant into something pleasant, although maybe that's possible too, but rather i'm talking about making something that used to be neutral or unnoticed, into something that is salient and pleasant). Things like sunlight, wind, sky, plants, watching cars go by, sounds, quiet, sunsets, clouds, reading books, art, etc.
Over time, i think this can make you signficantly happier, because these sorts of things are often available everyday, nearby where you life, and they are often available even when your life is otherwise going poorly.
In addition, enjoying these things appears to alter one's mindset in a way that might be described as 'more balanced' or 'more sane' or 'more calm', which allows you to make better decisions in other areas.
You should have some goals, because:
However, sometimes you should NOT have goals, because:
Chronic sleep deprivation greatly reduces your enjoyment of the little things, makes you more prone to being stressed out, and reduces your cognitive ability. These effects can persist much longer than the duration of the sleep deprivation itself; it may even be possible for chronic sleep deprivation to cause permanent damage if it is long enough and severe enough, although to my knowledge this has not yet been conclusively proven.
Regular aerobic exercise has been proven to improve mood and cognitive ability.
You can have serious medical problems and still be happy, but it's harder. The cost of living a healthy life is worth the reduced risk of bad things happening to you later. E.g. don't smoke because you may get cancer, etc.
"Mindfulness" forms of meditation have been proven to help control anxiety.
Every now and then, meet new people, go new places, do new things, even consider trying new activities that go outside your 'comfort zone'.
instead of maximizing something good, maximize either the difference between, or the ratio of, something good to something bad
This pattern generalizes to the corporate context.
before undertaking an action that will require spending some potentially-varying amount of a resource (for example, spending time on an activity, or spending money on a project), estimate how much of the resource will be spent. If, during the execution of the action, you find yourself requiring significantly more of the resource than was estimated, re-consider whether this is worth it to you. Afterwards, contemplate why you mis-estimated, so as to improve your estimation skills in the future.
This pattern generalizes to the corporate context.
So, a person who has trouble with vice X will often be overly suspicious that others' behavior is due to this vice. This makes sense, as people can't directly access others' internal thoughts but can access their own, so we are forced to use our own mind as a template for constructing models of others' minds.
People like it when you know their name. Some people are even offended if you forget their name when you "should" know it. There are various strategies for remembering people's names and associating them with their faces.
Note: this is culturally-dependent; in some cultures/situations, people will be creeped out if you smile at them without knowing them/without reason.
In many situations, the situation could be thought of as an instance of one or more archetypal social situations. These social situations are often shown on TV and in other media. Even if you don't think of it this way, others may be guessing what the probable outcomes of the situation are based on what happens in the archetype. If you don't know what to do, you might ask yourself, "What is the correct/common thing to do according to the archetype?". Similarly, if you want others to do something, you might ask yourself, "How can i make this situation more like an archetype whose most probable outcome is the desired action?".
It is often unclear what you can do without bothering other people, that is, what the limit is. You could determine the limit by systematically getting closer to it until your go over it, and then noting that other people have been bothered, and then retreating to the last behavior that didn't bother them; this is 'limit-testing'. But this strategy in itself is obnoxious.
In some cultures, "it never hurts to ask", and it's not rude to say "no" ("asker culture"). In other cultures, it is considered rude to refuse a reasonable request, and therefore it is also considered rude to ask something that the other party would not want to say "yes" to ("guesser culture" because the would-be asker must guess whether the counterparty would want to say "no").
Try not to create a scenario in which one or more people other than yourself don't have any options that don't offend or at least annoy other people.
expansion: coming up with and working out new ideas, learning about related things, adding functionality
contraction: finding unifying principals, combining similar ideas into one general idea, simplifying, removing functionality whose complexity cost isn't worth it
"I have noticed something in my mind: When I start writing down my ideas, my brain gives me more ideas like that. It's like my brain goes: "Hey! You're paying attention! You like that? Here, let me give you some more."" -- Lion Kimbro
in this context, by 'productive' is meant those constraints which are (a) amenable to formalization, (b) tractable to work with analytically, (c) tend to generate many lemmas when combined with the other hypotheses/concepts/constraints that you are working with/considering.