Can anyone recommend some tips to curb sugar cravings?

Hunger is extremely complicated in terms of all of the different controls, but one very important control is insulin. Insulin is a strong appetite inhibitor. So although directly after eating a sugary meal your hunger is satiated (sort of... there are psychological influences as well), it will return when you get the dramatic fall in insulin levels once your blood sugar has equilibrated and you'll crave sugar once again. One dietary way to decrease this effect is as you mentioned, by eating fruit. The type of sugar in fruit causes a more gradual increase in blood sugars and therefore a relatively blunted insulin response in comparison to a donut. Intermittent stress throughout the day can also cause sugar cravings, so if you feel like this may be a factor in your case, you may want to find a better way to manage your stress.