In this tutorial, I will explain my workflow for taking this photo:
and turning it into this one that has the quality of a botanical illustration:
Step 1 - Diptic
Insert the original image in both the upper and lower frames of a Diptic 2-photo square layout. (This step is optional - I did this to make my image look like a circle of flowers)
Next, flip the bottom image so it creates a mirror image of the top one and then decrease the white borders. Save results. (This could also be done by using any of the apps that produce mirror images)
Step 2 - Snapseed
Open Image 2 in Snapseed and adjust Tuning Brightness -10, Ambiance +20, Warmth +25. Apply changes and adjust Details: Structure +50. Apply changes and save.
Step 3 - Tangled FX
Open image 3 in Tangled FX and adjust to your liking (to view one of my customized Tangled FX formulas, check out this post). Save changes.
Step 4 - Painteresque
Open Image 4 in Painteresque and use Painteresque2 Style - Save changes.
Step 5 - Tangled FX
Open Image 5 and run it through Tangled FX one more time. Save changes.
Step 6 - Snapseed
If needed make final adjustments to Tuning: Brightness -10, Ambiance +20, Saturation -10, Warmth +20. Apply. Finally apply a Center Focus and adjust Blur Strength +40, Outer Brightness -60 and Inner Brightness +35. Save Final Changes
Here are a couple more samples using basically the same technique. If you find your edited image is too strong, you can always tone it down by combining it with one of the earlier stages using a blender app like Image Blender.
Every morning when I wake up, before I grab my cup o’ Joe, I grab my iPad. My ritual starts with checking for app updates and I’m always excited to see the little superscript numbers on the blue App Store icon! This morning when I clicked to see what was new, I literally got an adrenaline rush when I saw the 
