The gap between a parcel arriving and the first color going on is where most avoidable problems get baked in. Ten minutes of checking and setting up saves an evening later, and there is one thing worth doing before you start that almost nobody thinks of.
Check what is in the box

A kit should contain a printed canvas, a set of numbered paint pots, brushes in a range of sizes, and a reference print of the finished painting. Ours also includes a wooden easel with the framed sizes.
Count the pots against the numbers on the canvas before you start rather than discovering a gap two weeks in, when the sky is half finished.
Look at the canvas straight away
It should be flat, or gently curled from being rolled, with no crease lines through the image. This is the single most useful indicator of how a kit was made. A canvas that has been folded for shipping arrives with pressed lines across the picture, and those do not come out with weight, with time, or with heat. Ours ship rolled in a tube for exactly that reason, and it is the thing our customers mention most often.
If a rolled canvas wants to curl at the corners, lay it flat under some heavy books for a few hours. Do not iron it. Heat on a printed canvas risks the print and the primer, and there is no repairing either.
Check the paint seals, and open one pot
Seals should be intact. Open a single pot and look at the consistency: it should be smooth and spreadable, roughly like thick cream.
If a pot has thickened, stir in one drop of water and no more. You can always add another drop; you cannot take water out, and over-thinned paint will not cover the printed numbers underneath.
Do not open the rest. Acrylic in a small open pot skins over quickly, and the colors you use most are the ones that will sit open longest.
The thing worth doing before you paint anything
Photograph the canvas.
Lay it flat under good light and take three or four overlapping close photographs covering the whole surface. It takes two minutes and it gives you something genuinely valuable: a permanent, zoomable record of every printed number, including the ones in areas you are about to cover with paint.
Later, when a region is half painted and you cannot read what was underneath, or when two adjacent grays are too close to tell apart, you can zoom into the photograph instead of guessing. It is the closest thing this hobby has to an undo button, and it costs nothing.
Set up before you open anything else
A flat surface, a chair at a comfortable height, and a lamp positioned above the canvas rather than behind your shoulder, so your own head is not shading the work. Water, a folded paper towel, and the reference print propped where you can see it without turning around.
Then start. Our step-by-step guide covers the working order from there, and our nine practical tips covers the habits that make the difference.
Between sessions
A kit is a project measured in weeks rather than an afternoon, so where it lives matters. If you can leave it set up, do. People who have to rebuild their workspace every time paint far less often.
If it has to be put away, a shallow box that holds the canvas flat with the pots beside it works well. Keep it out of direct sun and away from radiators, and make sure every lid is properly seated before it goes in a cupboard.
If you are buying one as a gift
Two things are worth planning around, and neither has anything to do with how fast a parcel moves.
First, give yourself time in hand rather than ordering against a deadline. December is the busiest month of the year for this category, and a kit that arrives in a rush is a kit nobody has chosen carefully.
Second, and more important, spend the effort on choosing the right design rather than on the timing. Difficulty in this format has very little to do with the subject and a great deal to do with how finely the artwork is divided. A design with large calm areas of sky and water is a kind gift. One built from a dozen small birds, or one painted entirely in pale tones, is a demanding one, however gentle it looks in the photograph.
The full range of designs is worth browsing with that in mind. And if the person you are buying for would rather paint their own house, their own dog or their own view, Custom Paint by Numbers builds a canvas from a photograph.