Inhalers for asthma, when used with a mask/spacer device, work just as well as nebulizer machines, with much less time and fuss. Here are some tips:

• For younger children show them on yourself, then have them "teach" a stuffed animal, and practice on you.
• Let them play with a new mask and spacer for a while before using it for meds
• If they don't like the mouth taste of the medication, let them have a potato- or tortilla-chip before-hand, to coat their tongue, and then give them a sweet treat, fruit, or sugar-free gum afterwards to wash out the taste (from Contemporary Pediatrics)
  
• For inhaled steroids (Flovent, etc), wipe around their mouth afterwards, and give them something to drink to wask out the medicine.