Lynn Seaton teaches that the four dimensions of the bow are WASP: Weight, angle, speed, and placement.
Weight is how much arm weight you apply. With German bow, it's also controlled by your thumb but I don't have any experience with French style, so I don't know what the analogue is, if there is one.
Angle is how flat or parallel the bow hair is to the string. You can orient the bow at an angle, 45 degrees, for example, to get a more agressive weight.
Speed is how quickly you move the bow across the string and is related to how consistently you apply arm weight to the string; you have to increase the weight slightly away from the frog. A good exercise is to play as slowly as you can while still maintaining a good tone. Then do that across strings, skip a string, play the G string and then the E string, and switch up and down bows.
Placement is where between the bridge and the end of the board you place the bow. Higher pitch registers above the octave usually require moving the bow closer to the bridge to get a pleasing tone.
A good exercise is to play everything you play, scales, etudes, bass lines, melodies, what-have-you, in TP with the bow, exploring each of the WASP dimensions until you find a consistently good tone.
In your specific case, ghost harmonics in TP with the bow suggest that you're playing with too little weight and/or dragging the bow vertically across the strings. A good effect for something to grab the audience's attention, but not a typical melodic tone. Another issue could be that you're not playing close enough to the bridge. Playing an inch above the bridge is usually too tight sounding, but three inches, might be about right. Last, pops and squeeks are usually caused by the string popping up from the board between fingerings. You can get away with that with pizz, although it still shortens your notes in kind of an amateurish way, but with the bow, it transmits that momentarily pitch change in octave into a pop/squeak.
As always, a good teacher shortens the duration of the mastery of the skill and with all of the on-line teachers out there now, I can't think of a good reason not to engage one.
Best of luck! Using the bow for us pizz players gives us an entirely new instrument to play. One that's much more melody and solo friendly and much more like a human voice than a drum. Well worth the effort!
