First things first, size your images down to the correct size when editing.
Although I have a tutorial on how to manually size your blog's images without using a photo editor, using this method will not help the speed at which your images load. There are some pros for that method, I personally like it because I have a Mac with retina display and it's the best way I can get my images really crisp on my screen. I've decided though, that page load speed is more important than a slightly more crisp image.
JPGs Are Fine For Blog Post Images
For the longest time, I've saved my images as PNGs. PNGs are awesome, but they are a much bigger file size, and that kind if quality really isn't needed on the web, only for print. Here's an example of the two below, you really can't tell much of a difference.
How To Optimize Your Images
If you have photoshop, it is quite simple. You just save your file as a jpg, change your quality level to medium, which will decrease file size, then under Format Options, select Baseline Optimized. If you don't have photoshop, here's how you can quickly optimize your images over the internet.
1. I've been using this Online Image Optimizer website, which makes it very easy.
2. Upload the image you'd like to optimize. As an example, I'm going to optimize my images from my old post "25 Fashion Poses for Lifestyle Bloggers to Feel More Comfortable In Front of the Camera."
3. You'll see the original listed first, followed by variations of the image that have been optimized. Save the image that looks the best to you, without giving up your quality. I'm picking this one, which is a savings of 82% over my original.... 504 kb vs 89 kb. Looks just fine to me.
I now only show 2 posts per page, versus the 6 I used to show. This one is a no brainer, and makes total sense on why it would help with page load speed. Here's how to decrese the number of posts shown per page:
1. Select the Layout Tab in Blogger
2. Scroll down to the main blog post area, click edit.
3. Change the number of posts shown. I personally only show 2. Then click save.
5. Choose Your Third Party Content Wisely
Third Party Content is anything on your site that needs information from somewhere else in order to load. For example, I now have a Facebook like gadget on my sidebar. That decreases my page load speed, because the widget needs to go to Facebook to retrieve the information it needs to load. Third Party Content can obviously be very beneficial -- I want more likes on my Facebook page -- so just make sure it is benefitting you in some form if it's on your sidebar. If it's not, ditch it.
These are the easiest things you can go do right now to make your page load faster. If you have any other advice on increasing page load speed, I would LOVE to hear it!