Lower strings have a warmer sound. This is way we sometimes play whole phrases just on the G string. The choice of string and fingering influences the sound.
#3 Lower point of contact
The contact point is where on the string the bow hair is placed. If you play near the fingerboard, the sound will be softer.
Improve your violin bowing technique
Enjoy my FREE mini Masterclass 5 Bowing Secrets to Create a Professional Sound on the Violin
#4 Less weight and slow bow
By using less weight, the sound will be softer. By choosing a low bow speed, the sound will also be softer. Experiment and discover the sweet spot.
#5 Place on the bow (bow distribution)
At the frog you'll have a stronger sound, while at the tip it's easier to sound softer and sweeter. Always be aware where on the bow you will play certain notes. This needs to be balanced out with the weight, speed and contact point I mentioned earlier.
#6 Tilt the bow
By tilting the bow in the direction of the scroll, you will play with less hair and the sound will get softer and sweeter. You can choose to tilt the bow just at the frog or throughout the whole bow stroke.
#7 Slow vibrato
A fast narrow vibrato can sound nervous. Make slow, wide and lush vibrato for more romantic pieces.