Which bits of MY kit would you use for macro if you had to?

Bend The Light

I am still messing with macro, and have not done too bad with the limited kit I have. I don't have money for a 'proper' macro lens, so I have a question about macro with the kit I have...

Canon 18-55 f3.5-5.6 kit lens
Canon 75-300 f4 - 5.6 basic zoom.
2x Old russian 135mm f3.5 manual lenses (M42)
1 x Super Takumar 28mm f3.5 manual lens (M42)
1 x Helios 28mm f2.8 manual lens (M42)
1 x Meyer Optik Gorlitz 50mm f1.8 manual lens (M42)
1 x Prinzflex 35mm f2.8 manual lens (M42)
1 x Pentacon 35mm f3.5 manual lens (M42)

2 of M42 2x teleconverters

1 x reversing ring EF fitting to 58mm thread.

10 x lens-lens reversing rings, various fittings, so I can reverse any of the lenses above on any other lens above.

1x set of macro tubes (manual only) consisting of 7mm, 14mm, 28mm (plus mounting 'bits'...

I have a big old flash which I can mount on a bracket above and left of camera for portable stuff, or on a tripod at various angles to get close for static at home stuff.

So, to the question (quite a big question, really!):

If you were me, wanting to use this kit for macro (bugs and flowers, for example), on a walk in the woods, in the garden or at home for static stuff, what would you piece together for your kit?

Lord Vetinari

Loads of possible combinations there but suspect I would stick to trying the 50mm reversed directly onto the body or perhaps used with the ext tubes either reversed or normally mounted.These combos should give you around 1:1 to 2:1 magnification range.
Brian v.