A few things - first, try and work the cleaner wax a bit, so you get the most out of it's cleaning action. That is, don't just wipe the product on the paint, but add a little pressure to better remove the grime on your finish. Second, apply in straight passes, horizontally and then vertically - this helps ensure that you don't miss any spots.

For claying, while some people do use a mix of car shampoo and water, I've also heard reports that this can degrade clay, which is why it's usually recommended to use a QD as lubricant. For a good, inexpensive lubricant, check out Optimum No Rinse (ONR) - pinoycarcare.com is selling a 8 oz bottle of concentrate for 510 pesos. You use ONR diluted at 1:64 for clay lube, so you get over 15 liters of lube from that small bottle. You can also use ONR for rinseless washing, as well as QD, so it's a good product to have in your arsenal.

As for adding another product on top, I would think that it'd be a good idea, since Mother's Cleaner wax (and most cleaner waxes) isn't that durable. Optimum Car Wax. a spray wax with durability greater than most OTC waxes, would be a good product to use; Collinite would be another option. I've also heard that Microtex Nanoglos is being reformulated, and that the new version will be more durable, so that might be worth waiting for.