Release arm weight into the bottom two strings.
Pluck the G and D-strings as you move your arm in a circle.
Then play down-bows on G and D-strings together, first without the 1st finger on the bow, then with the 1st finger on the bow.
The 4th finger and thumb should support the bow in the air - of course, the 4th finger must be curved.
The free arm movement allows the weight of the bow and bow arm to produce a ringing sound, without any pressure from the bow hand.
Practicing without the 1st finger on the bow helps you check that this finger is not pressing.
Also, develop the ability to land and settle the bow on the string before playing the note. This will give a clear start to the note....