Start with asking other teachers for ideas. Doing everything on your own is exhausting. You don't have to like the entire lesson and use it exactly as they do. Change it to your style and what makes the lesson interesting for you.
Finding ideas can be frustrating as you go to the web. It seems that there are numerous fantastic ideas out on the web for all science subjects, except Earth Science. Just searching "Earth Science" inevitably brings up numerous lessons on the rock cycle, as if that is the only topic that is Earth Science. Looking through science supply catalogs is just as frustrating for the same reason.
I have better luck using the web when I know exactly what topic I am looking for. Be specific in your search. It doesn't have to be attached to some Earth Science curriculum page or an Earth Science recourse. Many of my favorite lesson ideas were found under Physics and Chemistry topic areas. It helps to think of Earth Science as really 4 different sciences: Astronomy, Geophysics, Hydrology, and Meteorology.
Keeping track of ideas from the web is also a challenge. Everyone has their favorite way. I have a file on my computer where I keep a list of webpages and downloaded documents that I have found. Pinterest has been really helpful for me as well.
To help you get started, here are some webpages and YouTube channels that I have found interesting and helpful.
I have also put a link to my Pinterest board of science ideas.
Utah State Science Core, also has links to lessons for different topics.
Science in the Parks (Weber State University) Activities Resources page.
Link to my pinterest science idea board.
Chemistry, Has some great properties of water lessons under Middle School.
Everyday people can participate in real science research projects in many different subjects.
Cool projects to play with.
YouTube Channel: Mostly Physics stuff but has some things that can apply to Earth Science.
YouTube Channel: Lots of interesting homemade gadgets if you are handy and want to make something really impressive.