Do you offset your annual carbon footprint?

More recently I've been focused on reducing my carbon footprint.

I buy and eat less meat, cycle to work when I can, motorbike if I need to, then car as the last resort if I've got too much to carry. I'm on a green energy tariff. I've also chosen a few domestic retreats rather than jet off to a different country.

The problem is those times when I do use my car, or have to fly because of work, or turn my gas heating on, as I start to feel a little guilty for doing so. So I started looking into offsetting my carbon footprint.

Googling it gives me a few options, and I've calculated my footprint at about 7 tonnes of CO2e. Not completely confident that's accurate, but it's a good ball park figure. They then give me a few options to pay for it, both global and UK specific options.

The UK one is tree planting and runs up about £100 for the year citing 8 tonnes will be offset. £13 a tree basically, all VCS compliant.

I'm going to do it, but wondered if there were any better options before I do, or what anyone else has done in this situation?