I'm often asked about my painting Equipment.  It's actually a complicated and forever moveable feast of kit which includes:

Winsor & Newton and Michael Harding artists quality paints.  I use a two primary system with raw umber for neutralising.  I always (I hope) carry a spare, "emergency" white.  Just in case I run out or forget to pack a white before leaving on a trip!  This has saved the day more than once.

Rosemary brushes - mainly, but not exclusively, from the Ivory Pochade range (short handles to fit in to the box).

Guerrilla Painter pochade 9 x 12 inch.

Winsor & Newton stretched artist quality canvases (the only ones to definitely be 9x12 to fit in to the pochade box).  It was a surprise when I first purchased a pochade box that cheap shop bought prestretched canvases were never the exact size stated on their packaging!   (This was an expensive error!)  Alternatively, I've begun experimenting with Jackson's MDF artists panels which I prime with Michael Harding's non-absorbent primer (in white or burnt sienna or neutral grey).  Panels can be attached to boards with blu tack.  Very convenient.

Various mediums.  Standard 50/50 oil and turpentine (with a dash of damar varnish) but also a basic glazing medium (5 stand 1 turpentine and 1 damar) and a complex slow drying medium that includes clove oil.

Various spirits.  Zest It - which has the added benefit of being odourless so can be used indoors.  Rectified Turpentine - which only can be used outdoors but is very fast drying.  I always keep a spare small bottle of Zest It in my rucksack.

The pochade box contains various other items - "The Masters" Brush Soap with a small bottle of water to use with it.  Cotton buds for wiping away and drawing in to paint.  Rags (lint free & plenty of).   Dippers.  Guerrilla Painter Mighty Mite Jr Brush Washer - a glass jar with a secure screw top which has an aluminium insert that separates out the mineral spirit/turps from any paint solids thereby keeping the spirits cleaner for longer.  Also, a toothbrush for splattering paint (great fun)!

I carry two palette/painting knives and a pencil with an eraser.  My current favourite being a Blackwing with a point protector on.

Lastly, I carry a ruler with a right angle and a very small spirit level - very useful for determining horizontals when painting the sea's horizon.

The box itself I put in a rucksack (not a draw stringed one but one that has a zip that goes around the whole of the body of the rucksack).  Such a fully zipped rucksacks allow for far easier packing.  

In the rucksack I carry: Hand Armour Barrier Cream to protect my hands from unwanted chemicals or elements present in the paint or mediums or spirits.  A baseball hat - absolutely essential piece of equipment to shade an artist's eyes when the sun is just too bright.  A STRONG umbrella.  A mat to sit on.  A bag for rubbish.  Small binoculars for bird watching.  And ....TREATS ... for those times when you're having to shelter under a tree in a force 9 gale or your painting isn't going very well.  Extra Strong Mints or Werther's Originals are my particular favourites.  Use well packaged snacks as it's not such a good idea to handle food after you've handled paint- you might not know what you're consuming! The same goes for fluids.  I like to take cartons of fruit juices.  Easily transportable and not confusable with any mineral spirit containers!

I also carry masking tape, business cards (with a blank back to write notes on) and a small bag of odds n' sods - bulldog and Bristol clips, paper clips, elastic bands. And not forgetting a pen etc.

Lastly, I carry a mirror.  Not to inspect my paintings in the usual way but to make sure I won't be walking around my neighbourhood with a face covered in Viridian paint after a particularly energetic pochading session! I already look peculiar enough :-)