When you're journaling it can be hard to find the right journal, especially if you're picky.
I recommend a small8-9 inch journal with plain paper so you can do your own thing and keep it easily transportable.

Here are some reliable choices you can use depending on what you like to do;

-Mossery sketchbooks. These sketchbooks you can customize by picking a specific design and getting your name printed on them. And they come in varying sizes, lined or no lined, dotted or graphed, and they're great quality paper for paints if you need.

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-Whitelines notebooks. The amazing thing about these are that the lines are almost invisible, so you can write straight, and not get distracted by them. They have graphed, dotted, lined, and plain paper. So you can easily write or draw or paste something, and it will come out straight. It also comes with an app that when taking a picture of the page, the lines disappear.

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-Also I would recommend a small ringed binder for if you want to take out pages or add more in. It can be very convenient if you're indecisive like me. And you can get them at your local supply store like staples or Walmart.

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You can always go with a regular moleskin journal from any store like Michaels or Target, or any spiral notebook if you're not picky. :)