Nice looking sabers you've got there MRG!
Like the leatherwork you did on the V3.
I guess you want a starting point for spinning, not for hilt buying or sparring techniques?
If so the here's my humble suggestion to start spinning:
1st, hold on to your saber.
The, hold on to your saber.
We can do a whole discussion about the way the fingers and hand(s) should be placed around a hilt, but let's not do that. Instead remind yourself to hold on to your saber. Especially during spinning it's sometimes very tempting to let go of your saber so you can get a nicer circle/form. Now think about what would/could happen if it really is a sharp blade... Or if the kids run around...
So hold on to your blade.
Then get comfortable with the balance of your blade. Where is the balance point? Balance it on your hand, in your hand, on your fingers, etc.
And start spinning
I would suggest focussing on the the following:
Forward spin right side (right hand)
Forward spin left side (right hand)
Forward spin left side (left hand)
Forward spin right side (left hand)
Same but with a backward spin.
Then 4x right, 4 times left and repeat.
Combine fw. spin into a figure 8 (1 turn right, 1 turn left, repeat)
Combine bw. spin into a figure 8
Combine both fig. 8's into a Fig. 8-set. Meaning 1 fig. 8 forward, turn your body, 1 fig. 8 backward in one continues flow.
Sounds basic, it is basic, but it wil be your foundation, so master it.
Don't focus on speed, focus on proper technique instead.
And again, have fun along the way.