I prefer lamp posts. They are magnificent looking and because they are high up, they provide excellent lighting.

It depends. If you are looking for a cost effective solution in terms of electrician then go for solar lights - particularly high grade / commercial grade solar lights, as these will last much longer and provide much better lighting at night, even on cloudy days.

Spike lights are good.

If you garden is right next to your walls, then you can't get past installing outdoor wall mounted spotlights and flood lights.

I agree that solar lights are the best alternative. They don't need any wiring, installation is DIY, and can be installed pretty much anywhere. Plus these days solar lights are excellent quality - they provide good lighting at night for many hours.

Solar fairy lights specially are good.