During endovenous ablation for the treatment of insufficient veins, failure to cannulate the entirety of the refluxing vein with the treatment catheter prevents technically successful ablation. In this technique report, we describe a defined protocol to overcome cannulation failure of axial veins for endovenous ablation. This protocol utilizes commonly available adjunctive techniques including ultrasound-guided digital compression, the use of a guidewire, the use of a guide catheter, and placement of a second puncture site in a step-wise fashion to overcome varying degrees of tortuosity or obstruction. The sequential application of these techniques as described in this report allows endovenous ablation to be applied to patients with challenging venous anatomy.