Flash assistance...

I recently purchased the 100L macro lens. I figured if I stunk at macro, I could use the 100mm.

Well, I stink at macro...
I am hoping that maybe with a little flash help, I can improve. I love the close up view of anything I have shot, I just am having a hard time with the lighting and seem to have my ISO up high to match shutter speed necessary to make a decent (not great) image. I shoot both freehand and with a good tripod/head. I can be real patient if I think I have a chance of success.

I have been shooting mostly with the 5D3, and even purchased the Kenko tubes. Talk about shallow depth of field.

I have a 580EXII.
I also have a bracket that I can move the flash around with, getting it off of the body a little.

What I am asking is, should I use some type of diffuser, and what kind of settings for the flash.

I am not good at bugs, so I am mostly taking flowers and such - painted surfaces, bark, rusted metal, etc...

Thanks ahead for any and all help.

The attached thread shows the weird and wonderful ways that we use to soften the light for macro shots. https://photography-on-the.net/forum/showthre​ad.php?t=142566

And the famous coke can diffuser. http://www.flickr.com …/macrovi...7594​312315664/

If you look for orionmystery posts, he links to a blog with some very helpful discussions.

As for settings, I tend to use ETTL, and then use flash exposure compensation settings on the camera if things are too hot or not bright enough.

Stick with it, I am basically useless by nature, and I am starting to get the hang of it.

The coke can diffuser works great for me.