Where you can you should register your designs. Broadly speaking this will either be by way of Registered Community Designs (RCD) or national rights, both co-exist so it is important to consider a combination of both an RCD and individual nation rights.
Prior to their registration all designs should be kept confidential in order to avoid losing their novelty (a requirement of a design).
Keep up to date with your registrations, make sure you know when renewals are due and pay them within plenty of time to ensure that the registration does not lapse.
All goods, documents and packaging should be labelled with the design registration number.
The last aspect is vigilance watch out for conflicting designs / infringements as there are no examinations or opposition proceedings for designs. If you become aware of infringements put them at notice of your rights.