Most if not all of the organizations I've been involved with apply them only as "needed". Here are some points you also may want to take note of:
1) Test any and all patches before they are applied to Production. Get approval and sign off on the patches (if needed) before moving them to production. I think this applies to most organizations but no one has the manpower to keep up with the daily/weekly patches. Many patches you may not need or use.
2) Any critical environment patches, you need to be aware of. Sign up for emailing of the notice of those critical patches from mylawson.com. All critical notices are also within mylawson.com.
3) Also become involved with your Lawson user groups so you can connect with other organizations which use Lawson.
Roger