Here on the East coast of VK 40 m is the band of choice for a quick activation. Next most useful if further away from the Sydney-Canberra-Melbourn- Adelaide line is 20 m. However 30 m can fill in some holes in coverage. Only if conditions are very good is it worth worrying about higher bands over here. Our nearest dx is 2,500 km away but most is 12,000 to 18,000 km away via short path.
I use a 40/30/20 m croclink dipole (link dipole using crocodile clips) and support it and its thin coax from various telescopic fibre glass poles from 4 to 10 m long. I use a stake in the ground for the pole and two pegs for the ends although sometimes tree branches and rocks have been used instead. It takes 10 minutes to put up with most of the time spent unwinding the wire and feeder. Dropping the pole section by section allows for a fast band change. I’ve found that, up to the stage where the mast splits due to extreme wind, no guys are required. I do sometimes align the dipole so it is end on to the wind and the stake is also aligned for max strength. They are a small section of arc of a tube cut length ways, so not flat but not a quadrant in enclosed angle. I have a steel stake with rings and aluminium stakes with velcro ties. There are always three masts ready to go in the garage. The stakes mean I am independent of trig points supports etc. I carry a small 300 g hammer to drive the pegs into hard ground and a piece of wood to avoid damaging the top of the stake when bashing away with the little hammer.
Tuned doublets with 7.2 m per side or 14.4 m per side fed wit 300 ohm line and a balanced ATU will give all bands from 40 m to 6 m with QSY as fast as you can tune the ATU. Some of us use these over here.
I’ve also used a G5RV, OCFD, EFW and 1/4 W verticals. The croclink dipole is still my preference for ease of erection and efficiency on 3 bands. I prefer to use an ATU to be kind to the PA but have had a number of activations without the tuner and no smoke was seen.