If you need help making the /f/ sound, watch this video. Remember to keep your top teeth on your bottom lip. Let the air flow out the front of your mouth. If you put your hand in front of your mouth, you should feel the air flowing.
If you need help making the /v/ sound, watch this video. If you need help making the /f/ sound, watch this video. Remember to keep your top teeth on your bottom lip. This is a voice on sound, so you should feel a buzzing on your bottom lip.
To practice speech sounds at home, try to aside 15 minutes a few times a week. Spend the first 3-4 minutes going through a word practice list. Then try practicing the sounds in a more natural activity, such as reading aloud or playing a simple game. See the Articulation page for more practice activity ideas.
I have lots more where this came from! I have many more resources that I just can't legally share on this public site. To request more materials for your child's specific goals, contact me! I will email them directly to you.