Don't give up. Take a look at the trail markers that you already put out and see if they give you a likely heading. Often times they can be like a road map. Follow that heading first and see where it gets you. Wounded deer will most often head for deep, heavy cover and/or water. They get thirsty after a wound and will do everything they can to get to water. If that water has heavy cover around it...check there very carefully. If that does not pan out, try a grid type search and always pay very close attention to heavy cover. If it looks "too thick" for a deer to get into, forget that train of though and look harder in that spot. It's amazing how they can contort thier bodies and get into tight spaces. It's like a mouse fitting thourh a dime size hole...how they do it is beyond me, but they do.
Best of luck.