It depends on where you are doing the glazing. According to the fat over lean rule, the lower layers of a painting should be lean and the subsequent layers should be progressively more 'fatty' to avoid cracking over time. Solvents, like odourless mineral spirits, will make the paint leaner so, while you could use thinner to make the paint more transparent, it should only be used in the lower layers of the painting.
Glazing tends to take place in the upper layers of a painting, so we would recommend using a glazing medium or stand oil to thin your paint.