Photoshop Tip: How to reduce the file size of your GIF
yeahps:
The first thing you have to do is download your video and create your gif. Add the sharpen, The text, The coloring,Crop it, Everything!
When it comes to keeping it under 10MB, If is a 500px wide gif, I recommend try not to make it of more than 20 layers.
The coloring can also help you to make the gif smaller. Making the gif Black&white can considerably reduce the size but If you want it with colors without screwing up the quality this is what you have to do :
1) Make the coloring the simple as possible. Do not use a lot of layers and enhance the blacks. you can do this on many ways:
On the layer palette select the adjustments (Half-black Half-white circle at the bottom of the layer palette) and choose the selective color . on the “colors” drop down menu select “black” and set the settings of the black to your like.

Also you can do it with the curves:
Again on the adjustment circle select “curves” and set them as you please but on “input” set it to something around 10 or whatever you please.

Or as well you can do it with the levels. On the adjustment circle choose levels and drag the hover arrow (the one on the red rectangle on the picture above) to the right.

2) Another way to keep the gif under 10MB you just simply create you gif and go to save for web and devices. Now on the drop down menu of the pop-up window look for this icon and click it:

And choose “Optimize to file size” and set it to 900K or 1000 like on the picture above.

Hit ok and This way the file will never exceed this limit.
Now just click Save and this is my result:

ALSO REFER TO THIS POST.