Once the tree is shaped the way you want it, you still will have some work to do.  Half the joy of sculpturing a tree is the added bonus of fresh, tree-ripened fruit.  To improve fruiting, keep after rampant growth by cutting back new growth to half its length in the beginning of the season.

In midsummer, stubs will put out additional growth.  Pinch this back to the last two leaves so the branch will produce even more fruiting spurs.  Chances are these insistent branches will send out even more new growth, which again should be pinched back.  A new tree, however, should be encouraged to use all its energy for developing roots and branches, rather than setting fruit.  The first year remove all the fruit buds.  By the third year, the tree should begin producing a limited amount of fruit.

It's true espalier gardening requires more effort per tree than other methods; the results, however, are bountiful, as well as attractive, enough to stop a passerby.