Here's a quick and dirty method to make goal post netting in about 15 minutes. If you'll spend more time on finessing the details, you can get even better result.
Step 1 - create a box primitive, make sure it has more or less correct dimensions compared to real world goal netting. This will be important later, when we'll do cloth simulation.

Step 2 - using edit poly modelling edit box shape to roughly match goal netting. You can use retopology modifier to get nice and even topology flow. Try to maintain polygons size equal to each other and their shape as close to square as possible. Don't make the model too low-poly, but also don't add to much polygons, as this will make your simulation unnecessary slow.

Step 3 - add unwrap UVW modifier and make good and clean UVs. Try to eliminate as much UV stretching as possible. This step is very important, so spend more time on it.

Step 4 - add cloth modifier

Step 5 - activate cloth sub-object level, select all the vertices that will be attached to the goal posts, press
make group and then
drag buttons. This will create new group from selected vertices and assign drag property to the group.

Step 6 - close sub-object level and press
object properties button. In the properties window select goal net object from the list, make it cloth and adjust cloth properties. You can use my screenshot as a guide, but keep in mind that most important settings here are U and V scale. Experiment with these two settings until you get satisfactory results. Other settings makes little difference to this sim, but you can use them to further tweak cloth shape.

Step 7 - close object properties window and press
simulate local. Observe cloth simulation. If you don't like netting shape, go back to cloth properties, change some parameters and press simulate local again. Repeat until you get acceptable result.

Step 8 - make tiling mesh pattern. You can use 3ds Max splines, or editable poly, whatever is more preferable to you.

Step 9 - select netting object and add Corona pattern modifier to it. Chose mesh object created in previous step as pattern node.

Step 10 - enter sub-object level and carefully adjust crop box, so the mesh would tile seamlessly.

Step 11 - adjust U and V tiling in pattern modifier to get mesh size that you want. Use interactive rendering while doing so, since Corona pattern is render-time modifier and its effect will not be visible in viewport.

That's it, you should have nice goal post netting model now. Enjoy! :]