If you're buying a second van your no claims discount only applies to your first commercial vehicle, but you may still get a lower quote if you haven't made a claim.
Steering locks and immobilisers are good ant-theft deterrents and may help reduce premiums if you use them.
Young drivers under twenty five should think about being placed on their parent's policy as a named driver, as insurance costs for young drivers can be high.
Even if you have had a poor quote from a van insurer previously, try them again as sometimes their pricing structures change.