Smaller plates are big help. I just bought a couple of cheap plastic kids plates and as they are half the size of on of my normal plates, I only put on half the amount of food.
Drink lots of fluids and eat loads of fibre to keep everything moving.
My typical day is (yes I eat 2 breakfasts and get up at stupid o'clock for work)
Breakfast 4am: 2 slices of toast with peanut butter and jam, cup of tea Breakfast 8am: bacon, egg and potato scone, cup of tea, pint of water Snack 10.30am: banana, glass of oj Lunch 1pm: pasta, 1/2 can tuna, pasta sauce, pint of water Snack 3.30pm: peach, 1/2 avocado, can of coke (my treat) Dinner 5.30pm: roast chicken breast, jacket potato, salad, pint of water Snack 8pm: crudités and hummus, pint of milk
Oh and I have to taste test around 10-15 things at work, so I pretty much eat all day. (I don't sit still, and have so far at 21 weeks put on just over a stone)
There are still days I'm bunged up, and I will take lactulose to help things along.
Swap all white carbs for wholemeal - wholemeal bread, pasta, wild rice etc. I'm not keen on wholemeal bread but for me it's worth it for the difference it's made. That's all I needed to do to sort my digestion out. I've heard a lot of people say there are specific foods that caused them trouble, maybe try swapping out various different bits of your diet til you can pinpoint the trouble makers.