Here's how I print my photos at home for pocket style documenting (aka my Project Life album). I usually want my photos to be 4x6 or 3x4 becuase I mostly use Design A pocket pages in my album. Before beginning, I thought I'd want to use a variety of pages, so I bought a variety pack, which I do occasionally use for inserts etc., but to simplify the process in order to keep the priority on getting it done, I found that I used almost only Design A. It helped me a lot to just get comfortable with using the one design throughout the year and I do like how it seems less distracting when looking through the book page after page.
So, above you see photos printed on either 4x6 or 8.5x11 photo paper. I use this 8.5 x 11 photo paper and am very happy with it. This is my photo printer for these two sizes when I print from my computer (mac). I love the printer, and can't believe the price right now! I use iPhoto, a photo editing program that came installed on my mac computer. In iPhoto, I created a folder called "PL to print". When editing a photo, I crop it to the size I want. In iPhoto there is a drop down crop menu that gives you a number of selections. I choose 4x6, 3x4, and sometimes choose custom to get another size I may be wanting. I can't stand to waste paper or ink, so I only print when I have enough photos in my folder to fill a page. The printer has a dedicated tray for 4x6 prints, for 8.5x11 I usually wait until I have 6 3x4's. On the right above you see that I have 9 photos that were edited to 2.5x3.5 and will go in this pocket page as an insert. It will be slightly thinner than the pocket, I just leave a little white border on when cutting.
When printing from my phone, I do something different. I take a lot of photos on my phone as well as screen shots etc. that I want to print for my PL. I recently bought this little printer (in white of course!) and it's made printing wirelessly straight from my phone easy, but it's got it's pros and cons. (When finding the link, I see there is a newer version with improvements, I would buy this one if I were going to get one now.) I like it a lot, but I wouldn't say I love it, mostly because the photos aren't true 4x6 in size, they are just a titch smaller in width, which annoys me when tucking into those pockets. I don't know if the newer model prints true 4x6. When I bought it on Amazon it cost $75.00 and was a good solution for me. I think the quality of the photos is great, no complaints other than you can't get semi-gloss photo paper cartridges that I know of. So, to print 2 photos on one 4x6, I use the method found here. I swear, the internet is such a great resource, so much information a google search away! Here is a link with lots of other methods people use, and here is a video tutorial using PSElements.
And there you have it, how I print my 4x6 and 3x4 photos for those pockets!