by "servicing", do you mean preventative maintenance before there is a problem?
For this, I would do myself. Basically check tyres, brakes and for any loose bits.
If however, something is broken, making a noise or obviously needing TLC, then I would weigh up the difficulty, do I have the tools, do I have the time and knowledge etc. Usually would try diy, but more than once have gone to the LBS. There are a few good ones round here and have always done a good job,
But would only ask the LBS to address the specific items needing attention.