An extremely effective tool is called the List of Positive Aspects.
One great time to use it is immediately after doing a Focus Wheel. You feel strong negative emotion about something, (worry, or overwhelment or frustration, for instance) and you make yourself feel better about it by doing the Focus Wheel exercise. Once you get all the way to Appreciation, you prolong and solidify the new feeling about it by doing a list of positive aspects about that situation.
Keep in mind, it is almost impossible to appreciate someone or something when you're feeling angry or irritated by it; you do a Focus Wheel about it first, and genuinely feel better (even just to get as far as to "make peace" or have "contentment" with who they seem to be) about it before you can easily come up with a list of positive aspects.
Also, it is something that you can pull out of your pocket when you are feeling pretty good and you want to feel even better than good. (and incidentally, lots of great stuff comes pouring down upon you when you do this regularly. But don't do it in order to make lots of good things come to you, because that thought is focused on the fact that you do not yet have those wanted things...)
The List of Positive Aspects is just that; you think of the subject and write (or imagine) everything you can think of that is positive about it.
Make it a habit. When you're in a situation you love, milk it. When you're in a situation that is uncomfortable, exercise your mind to focus upon anything in the person or situation that is positive. If you're ever in a situation when you can't think of positive aspects, go back to the Focus Wheel to get closer to Appreciation.
Everyone seems to have positive and negative attributes. Here's a personal example:
Before I learned about Law of Attraction, I had decided a person in my life was horribly thoughtless and disrespectful. Every encounter with him proved me right. It felt really bad to think of him and to be around him.
I eventually realized my belief about him was effecting my interactions with him.
I did a very quick Focus Wheel about it; starting with the statement that I thought he was unkind and thoughtless, etc.
The statement I wrote at the bottom of the page that I wanted to believe (but didn't) was that this person was generous and kind and well-meaning, etc.
I then wrote statement that I did believe that supported the wanted belief.
I remembered and wrote about an actual example of generosity.
That focused thought (because of Law of Attraction) led me to many other examples of generosity and kindness on his part.
I then easily made a list of positive aspects about him.
Every encounter with him from then on was delightful and fun and funny and full of examples of his loving nature.