I used Vaseline on Max when he was going through the awkward stages of hair growth. As Nancy indicated, use only a tiny dab and put it in your palm first. I also used PetSilk topknot gel.
If I recall correctly, I was still trimming Max's "eyebrows" at about 5 months of age. By 8 months, he had a pretty good topknot, but I was still fighting the mustache, trying to keep it out of his eyes. Depends on how fast your dog's hair grows.
Here is Max at a little over 5 months with hair sticking in front of his eyes, lol:
