I don't have any Trick Arrow characters, but for my single-target holds (on non-DPS AT) I definitely try for 5x %damage, plus something. For a power like Ice Arrow, which is available for low level content I typically look for something to boost Accuracy and the secondary effect (here: Hold).... and sometimes even Endurance! Entomb, Endoplasm, Unbreakable Constraint and Gladiator's Net all offer something.
YMMV, but here is something I keep an eye on. Psi damage is widely resisted by a large number of enemies, it's %proc I can pass on...so if one of the other %damage pieces is PVP Gladiator's Net %Lethal I will usually consider dedicating two other slots in the single-target hold to Gladiator's Net (level 50+5) Accuracy/Hold and Accuracy/Hold/Endurance/Recharge. I'll run the spreadsheet to see how badly a boosted recharge in the 4-banger is affecting proc rates, but usually I appreciate the extra other boosts more considering the inherent cycle time of single-target powers). My reasoning is that the 3-piece PvE set bonus for Gladiator's Net is a global 2.25% increase in Total Endurance. This means final slotting will be something like 2xGladiator's Net (including %Lethal) with three other %damage procs.