At this stage, I gave special attention to the shape and amount of parts, so that the composition would be nice. There was no need to cut down on polygons, because I was planning to do a retopology later. This allowed me to make use of many details.
Once all the basic modeling for the weapons and accessories was completed, everything was exported to ZBrush where I was able to give fine details to the mesh of each part (Fig.04). If your machine is not equipped with 8GB of RAM and one of the newest processors, I recommend not exceeding the limit of 10 million polygons within ZBrush.
Another tip is on exporting. I recommend using Decimation Master to export high mesh files, as this can smoothly reduce 50% of the polygons and make it easier on the software that will generate the normal maps.
With all the high modeling complete it was time to get the retopology started. When retopologizing It's good to keep in mind what will be in motion and what not, because if you make only one mesh for objects that should be independent you won't be able to freely move them in the future.
Another good tip is to put the vertices and edges in strategic locations as well as edge loops, so that you can increase the quality of its mesh.
For the retopology of my character, I did some parts full-mesh (Fig.05) and in other took the base mesh. One example can be seen in Fig.06 where I chose not to convert them into editable polys, so I just needed to reduce the 3ds Max defaults.
Fully equipped the total got up to at 29,704 polys and 21,309 verts. A high value, but the right amount for the character.
Now that all mesh files, both high and low were ready it was time to get the maps started. One thing I've learned recently about mapping characters is that you need to avoid leaving a UV cut exposed as it could ruin all your work! Especially when you're in the same situation as mine, where you're developing a character for a game, because the engines usually set where the cuts. Unreal Engine is no different; it makes sure that the UV cut is noticeable to anyone. The trick is hiding cutting at all costs.
Fig.07 shows how I cut the UVs. I don't know if it was the best way possible, but it was enough in this my case. I knew I would hide most of them with the equipment of the character so I wasn't too worried.