Thanks to XRG81 for providing detailed low poly texture painting and UV unwrap tutorials in Blender.
Some of the things I have learned:
Simply drag reference image into blender Front viewport.
Hold [CTRL] while using inset [I] to extrude.
Press comma [,] for orientation (axis) wheel menu.
Press period [.] for pivot wheel menu (center of rotation / scaling).
Press [SHIFT][S] to set the cursor to world origin.
For symmetrical objects mirrored along a world axis, when in edit mode you can scale vertices / edges around the cursor in the origin to stop them from entering the mirrored side of the object.
When in vertex mode with vertex snap enabled, you can press [A] to mark surrounding vertices. The selected item will now move averaged between these vertices. This is very useful for centering objects.
To connect separate parts in your single object, make sure they overlap. Then use [Faces > Intersect (Knife)] to create edges where the faces intersect. Make sure to select [Source: Self Intersect] in the popup tool panel.
Select a single vertex. Press [SHIFT][CTRL][B] and move the mouse to perform a bevel on vertex level.
Things I have learned:
For the blade and pommel, use ‘project from view’ unwrapping in front view.
For the blade guard and hilt we want edges laid out as straight lines for painting so we use ‘follow quad’ unwrapping.
For the guard:
Select a single quad.
Select two vertices and align auto (SHIFT-W)
Repeat to make perimeter a rectangle.
Select all linked [L]
Select all faces that can be laid out in straight lines.
UV > Follow active quads
Unwrap remaining polygons clusters (top, bottom, jewel)
Make remaining polygons clusters perimeter rectangular
Scale to fit insertion point
Select vertices around perimeter of insertion point on the guard UVs
Useful for ‘project from view’ when object is not aligned with a standard view (front / top / right)
Selecting (linked) polygons and using a Fill Brush:
When texture painting, to see what you are doing, set the viewport shading mode to ‘Solid’and disable lighting (‘Studio’ > ‘Flat’). This will disable glossy highlights and dark shadows and only display flat colors.
It is important to mark sections of your mesh as ‘seams’. This will allow you to ‘Select Linked’ [L] when using texture paint mask ([M]):
Paint Mask [M] allows you to ‘select linked’ and isolate a part of the mesh the paint brush affects. Think ‘coloring inside the lines’.
You can also use Box select [B] and Circle select [C]. Use the mouse scroll wheel to change Circle Select size. Drag over a polygon to select; drag over already selected polygons to unselect.
Using Soft / Hard brushes and Space / Line strokes [E] we can paint in highlights and shadows: