For a shinier coat, feed a cup of corn oil a day with his grain. An article recently came out about the cons of feeding corn oil, but it has always worked for me. I don't clip my hunter/eventer, but I do blanket him so his winter coat isn't as obnoxious for late winter shows. His mane is pulled around this time of year and maintained throughout the show season. If you really don't want to pull his mane, you might be able to get away with a neat running braid, but it depends on what association you're showing with.