My favorite journal is a brand called Moleskine, it's a small black leather covered book made in Italy, the paper is fine grain and it has an envelope in the back for notes... it fits into my bag and I have a smaller one for my purse. They can be purchased at any good bookstore.
I write notes, add photos and interesting things, like tickets and I love drink coasters so they are collected too. For instance, I saved the ballet tickets from Mexico... and the underground tickets that cost 20 cents....!!!! they are wonderful trigger memories.
There is an exercise that I do with some of my classes.. and in July I have a retreat in Michigan where we will be doing this activity. (my class will be bused from Grayling Michigan to Macinaw Island)
I ask students to take a walk with their eyes open.
On the Macinaw trip we will look at things just a little differently, and we will discuss them as a group....and then the students have an opportunity to go off on their own if they wish to discover.....
Maybe we will discover the edge of a leaf with the light shining through.
Maybe it will be the color of the lilacs in bloom or some of the wonderful doors on the houses that look like wedding cakes....
I ask my students to sketch a number of things. A leaf, a flower, a color combination.....It doesn't matter how rough the drawings are, the act of putting pen to paper is very powerful.
Your Journal becomes your friend and an extension of the way you think.