How can I attach sensors without a shield for a wearable project?
The accelerometer may be pretty easy (since it may not need to be in close contact with the person), but the GSR and skin temperature will need to be touching the person to work.

The first thing you will want to do is to identify the sensors that you want to use, and then come up with some ideas for how to make them wearable so that you can measure the parameters that you're looking for. Will you be able to attach them with straps, or does the attachment need to be more subtle or more comfortable? Small breakout boards are handy, but they may make the sensor uncomfortable to wear.

I'd suggest taking at look at the Adafruit site for some ideas on wearables and sensor interfacing. There is a lot of useful information there and much of it focuses on Arduino based designs. For the most part the sensors they sell and use are well documented either with data sheets or code (or both).