Like many who have worked with Epoxy resin for a while, I have become sensitised to the resin. My hands and face now both react to contact and even to the fumes. This started over 30 years ago when I built racing dinghies. Had I followed the tips below, I believe I would never have the problems I now have. These are my own thoughts to help, but READ THE INSTURCTIONS THAT COME WITH THE EPOXY.

• Wear Latex or Nitrile (some react to Latex) disposalbe gloves, and do not try to re-use them
• Work with good ventilation. We'de all like extrractors, but for most it is not an option
• Ideally wear a mask, particularly when sanding, but even when laying up
• Have lots of prepared rags and acetone ready to clean things
• Epoxy is very sticky, and gets onto the tools you work with. Ideally you would have tools only used for epoxy work, but in the real world, clean your tools with acetone when you have finished that job using a clean pair of gloves and rags you throw away
• Door handles sometimes get opened in a hurry with epoxyied hand, so wrap a wrag round any handle you are likely to open near you, and remove when you have finished with epoxy that session
• Some epoxies are less aggressive than others. I started using an aggressive resin for this project, and later moved onto one called "Sicomin", in the UK sold by Matrix. It did seem to help with the fumes, but my hands still reacted. So a partial win. If you don't have a problem already, probably not needed, though if working in your house, the almost lack of smell is very pleasing.
• Soap and warm water is surprisingly good at cleaning epoxy, so use a scrubbing brush on hands with soap and warm water. Some even clean tools with soap and warm water
• Epoxy is active for some 30 days or so after it has been layed up. So if you sand it within that period, remember to wear protective clothing
• I wear cotton liner gloves under the nitrile gloves, good if you already have sensitive skin.
• Shower after finishing a session is good if it fits in, though not always realistic
• On a similar vein, wash your work cloths often
• When adding filler powders, definatly wear a mask

Hope this helps