Hi Sharif, so here's an example with some steps.

Initially just focus on the full form that underlies the entire shape, don't worry yet about all the criss-crossing parts or holes, just get a big surface to start with, something like this:






Then you'll want to get some criss-crossing patterns that hug that surface, here I've drawn in a few lines and used Construct > Curve > Project to project them on to the surface:





You'll probably need to fuss with this part quite a bit to control the pattern that you want.

Then you want to make that pattern have some thickness to it, and the easiest way to do that is to do some sweeps with just a circular profile to make some tubes like this:



Then those tubes intersect the main surface leaving a kind of thickened trail.

You can at this point actually do a Boolean Intersection between the main surface shape and the tubes to get the areas of the surface which are contained within the tubes like this:



But that may have some difficulty finishing well if you get quite a huge number of things all kind of crossing over each other. So you may need to do a more low level surface trimming approach.

That would involve using Construct > Curve > Isect to intersect the tubes with the main surface to produce intersection curves like this:



Then trim those curves with each other to remove pieces you don't want, like this:



Then you can trim the surface with those curves.

Hope this helps!

- Michael