best tips to prevent fleas in my west highland white terrier?

i am really scared of my dog possibly getting fleas in the future, cause fleas are just disgusting.especially for this type of dog: a west highland white terrier (westie), what are the BEST and most EFFECTIVE ways of PREVENTING fleas (and other parasites).all personal testimony (personal experience) REALLY helps!i really truly appreciate all help!

Our dog Shiloh has a severe flea allergy, since before we rescued him and his back end is hairless. The vet said it was so severe if he got infested it could kill him so we use Frontline plus for dogs, all you have to do is put the topical medicine between his shoulder blades and he will be all set until you do it next month. Also, get an exterminator out to your house so he can spray the backyard to kill the flea and ticks. Hope this helps.