Step 2 is the lay-in, or first general application of oil colour. With this method the whole canvas is covered in a general way, which is then refined with more detail. An alternative method is to work up detail on small areas at a time (e.g. as used by the Pre-Raphaelites). This requires an accurate underdrawing and can result in sacrificing the whole to the detail, as was sometimes the case with the PRB. I digress.
Since I was going for a glazing approach I used a medium consisting of linseed oil, Liquin Light Gel (Winsor & Newton) and low-odour thinner (Sansador). The Liquin Gel speeds drying (so you don't have to wait ages before applying the next layer) and is good for glazes. The Gel dissolves and mixes with the oil. I also used a white palette (one of the tear-off disposable types) as this shows up the transparent colours. (For the dark background I used a mixture of Burnt Umber and Ultramarine Blue. This gives a transparent 'black' that is much better than using black paint, which sucks light in. I also used this mixture with Titanium White to give opaque greys that were used for the fabric. For the lemons I used a good Lemon Yellow (Mussini), a semi-transparent Permanent Orange, a little Cadmium Yellow Deep (with is semi-transparent if applied thinly), Raw Umber, Ultramarine Blue and a violet, as well as a bit of the transparent black mix. I probably didn't need all these colours. I also cheated a bit an used a bit of Titanium White to lighten the highlights. This is OK at this stage as I will glaze again, but you should try to avoid white as it will kill the transparent effect. Violet (mixed with the 'black' mixture) was used for the dish.
OK here it is (click on image to zoom):
Step 2. Initial lay-in with oil colours
By the way I was working from the image on the screen on my laptop (set up at the same height as the easel). I have worked from the actual set-up in the past, and this is probably the best method, however there are drawbacks. The subject has to be lit correctly and consistently, and it can be difficult to also light the painting. The easel has to be set up at the correct height. The subject can change over time (particularly flowers and fruit - lemons are not too bad). Also, as I mentioned, I have manipulated the image on the computer. Anyway my method is maybe not for the purists, so forgive me.
I need to let this painting dry a bit before the next step.