Solar cells connections (Quora)

What is the best way to connect (small) solar cells to get higher voltage and current?
I have these 0.5v 0.4 A max solar cells and i would like to get 15v max output, so i know i have to connect them in series, but do i connect them all in a combination of series and paralel?

Here's a visualization of what I'm thinking:
Series first and then paralel:
|- cells - cells - cells -|
|- cells - cells - cells -|
|- cells - cells - cells -|
+                         -

Paralel first and then series
|- cells -||- cells -||- cells -|
|- cells -||- cells -||- cells -|
|- cells -||- cells -||- cells -|
+        (-+)       (-+)        -

(These illustration uses less cells than what I'm going to actually use, i have a lot more)

Hopefully that explains what I'm talking about, I don't really have that much electronic knowledge (just youtube and highschool knowledge really). But hopefully that illustration makes it easier to understand, basically the question is:
Is it better to connect my solar cells series first (to achieve higher voltage) and then connect them in paralel (to achieve higher maximum current) or is it better to connect them in paralel first and then combine them in series?

Note: By better, I'm talking about which one is safer, and is more efficient. My plan is to get around 15v at 4 Amps maximum, so i want to make sure the way I'm making these connections are the best possible, so they can output as much energy as possible while being the safest it can be.
I will also be adding a solar controller to the output with a battery and maybe an inverter. Its also not going to be used for anything important or serious, mostly just for fun and experimenting with solar power. If there is also more components that are important to make it safer that would be great!