This is my current setup for urban sketching nowadays.

• Watercolour sketchbook
• Water bottle
• Tissue
• Water spray bottle
• Fountain pen
• Pocket watercolour brush
• Watercolour Palette
• Clips

This setup can be even more minimal by using a waterbrush instead. In which case, there's probably no need to bring water bottle and water spray bottle. Using a waterbrush will also allow you to stand and sketch.

I still prefer to use a proper watercolour brush than a waterbrush though.

Watercolour sketchbook

That watercolour sketchbook with the wave design is a customised sketchbook (with Arches watercolour paper) made by Jeff from Amono Studio. It's the sketchbook I happen to use now but not one that I use all the time because I'm always testing out new sketchbooks.

Generally speaking, if I don't have any sketchbooks to test, I would just use the SPD custom made sketchbooks with 100% watercolour paper.

Nowadays, there are so many options for 100% cotton watercolour paper sketchbooks. These are great for those who want the best paper, but they are obviously going to be more expensive.

Fountain pen

The fountain pen I use most frequently is the Pelikan M200 with a fine nib. I like this pen because it can hold a lot of ink. I've been using it for years and it still works great.

I also use the Pilot Penmanship for the EF nib for drawing extra fine lines.

Pocket watercolour brush

There are many brands of pocket watercolour brushes out there, namely Escoda, Da Vinci, Rosemary, Holbein, Jackson's.

I like Da Vinci's pocket brushes because I like the screw on body where there's no chance for the joint to wiggle or move.

The one that I'm using now is the Da Vinci Casaneo pocket watercolour brush. The synthetic hair performs quite comparably to sable hair.

Watercolour palette

I'm alternating between the bigger Portable Painter Palette which has hold 12 pans and the Micro Portable Painter Palette which holds only 6 colours.

The Micro Portable Painter is about one third the size of the original which makes it really portable.

The Micro Portable Painter can be clipped to the corner of the sketchbook which makes the painting setup very convenient. This also allows you to stand and sketch.

The paint in the palettes is mostly Daniel Smith watercolour paint.

Bag

This is the CommuterPak (review) from Funk St Outfitters. It's a compact cross-sling back just big enough to hold all the art supplies shown above. The limited space will also help you reduce the amount of art supplies you can bring.

The bag is big enough to (barely) fit an iPad Pro 12.9 inch, so it's a good bag for a digital sketching setup too. This is a more minimal setup than the traditional sketching supplies setup.

I used to use a messenger bag or backpack but this CommuterPak cross-sling back is more portable.