Severly deforemed and angulated fractures often pinch off blood vessels, compromising circulation to the limb distal to the fracture. What is generally taught these days in WFR and WFA classes is to attempt to use very gentle traction to move the broken limb into (more or less) normal anatomical position, prior to splinting. This is generally more comfortable for the patient and has better outcomes, particularly if transport to a hospital is delayed. However, if you meet resistance when you try to traction into position, or the movement causes extreme pain, then splint in the position found.

Splints should immobilize the joint above and below the fracture. For example, for a broken forearm, you might want to use a SAM splint to imobilize the the wrist and forearm, then support the splint with a "sling and swathe" to also immobilize the elbow. Splints should be well padded and easy to adjust to account for swelling. Check CSM (circulation, sensation, and movement) distal to the fracture both before and after splinting. Frequently check CSM distal to the injury, since swelling can cut off circulation after splinting. If over time you find CSM is becoming compromised, then you need to adjust the splint to maintain circulation.