Still trying to get good result, did I overthink it ?

Hi Xavier! It is great fun, and sometimes great frustration, to try out new gear! You are definitely off to a great start.
You mention a couple of things here.

F1.4 is pretty shallow. You run the risk (as happened here) of just missing the leading edge by a hair. While I'm sure others will disagree, i think you will be more successful staying at or above 2.8. Just personal feeling coming from too many "just missed it" personal experience. Your on the right track for getting this great DoF though. If I were trying for something like this I would go with 2.8 and try to catch the front of the subject in the middle of the focal plane but the DoF would still be really tight. The leading edge would all be in focus with a quick transition immediately following. (Hope that makes sense!)

I never take my camera off the tripod. Seriously. Never. I set my shots and use a remote shutter release often. Even when panning. I just don't hand held. Again, others will be different. I just don't have a steady enough hand! And in a situation like with your shot, it is hard to make minor adjustments between shots if you change the position of the camera between each. Put it on a tripod and take this out of the equation. Then shoot, check it out, adjust and shoot again. Tripod is key.

I would also suggest a few post processing tweaks that would make this image really pop but would ask your permission/interest before posting an edit.

Lastly, there is a group Minimalism, Abstract, Experimental that is a good hub for experimenting like you are doing. Check it out. Its a pretty open forum.

:)

Hello Xavier! I completely agree with everything Ruth said, with that said, I do have a few things I can add. I also have a bad habit of always shooting hand held, but I'm trying to get that in check.

When it comes to post-shot edits, that is a lot of magic to an image. I would see these amazing macro images and get really frustrated when I couldn't get anywhere near the results.

Working with 1.4 is extremely shallow of a field, but take several shots while moving slightly forward and back. Now say you have 5 shots that are very similar (nearly identical to the eye. Bring those into Photoshop as layers, auto align, then focus stack... Poof! Now not everyone dose this, but it is rather huge, specially working at such a shallow depth of field.

Subject separation is also vital and this is also modified (changed) by some macro shooters where they will use clips to move a target away from the background several inches forcing separation; then nail just that target with the focus plain. I'm learning there are a lot of little tricks done in macro.

You may also find a "macro" lens more suitable for really close up work. I own a 15mm "macro" and my front element can almost touch the subject and the lens can still focus. Downside is that it is a fully manual lens... But as I mentioned about, I'm mainly moving myself in and out for focus instead of using auto focus anyway. Though it is a "slower" lens at f4, an example can be seen in my profile (the image with the frozen berries). I have even done some macro work using my 200-500mm lens (@750mm equivalent). Macro rings are also an option.

When it comes to landscapes I find myself using the 18 to 55mm kit lens (@18) the most (27mm equivalent). I'm saving my pennies for a 20mm full frame setup. That is not to say you can't use the higher mm lenses for landscapes; I often use my 70-300mm lens.

I just woke up and I am kind of rambling here, so I'll stop for now. Hopefully there were a few nuggets in the above. We are all here if you have questions or thoughts of course. :)