BGP/OSPF router security

Hello all, I have a single FreeBSD/bird router running BGP and OSPF. I have two full bgp feeds and some IXP sessions. Some of my users are subject to DDoS attacks which basicly kill my router. Is there anything I can do to make things better? I was thinking about adding a second router and having one full bgp feed per router. I was also thinking about joining BGP Blackholing project. But - the question remains - what else can I do to survive a ddos, or at least be able to react when a ddos occures? All best, Jim