Here are a few vocal warm-ups.
Continuant Consonants: Many nanny meaning leaning kneeling railing raining real
Unvoiced Consonants: chair care tar par tacky chatty catchy
Partially Voiced consonants: Bar grill deal Jill good dead jade bread
Fully voiced Consonants: Very measure zero they treasure mere Zen then
Aspirant, or Whispered Consonants: Who how flew show three see shy thigh
Use a slow but steady pace
When practicing your high notes, start in the mid-range and then practice singing higher and higher. Practice your scales going from the low note to the high note and then back again.
Sing: Mah——————— Mah ————————-
Find your vowel
Singers have a particular vowel that works best for them. You have to find yours. This is called vowel modification. Experimental singing will help give you an idea what vowel works best with your singing voice.
Day, say, pray, may, dry, whine, line, cry