I like to grill twelve months out of the year. It is more difficult to grill in the winter, you just have to know how to time it better. Keeping the cooking simple in the winter is also a must. That being said, if you are one of those people that puts away the grill for the winter, spring is a great time to completely tune it up. Be sure to bite the bullet and not only refill your propane tank, have a backup tank for when you fire up the grill in late June, only to realize that you are too low on LP to cook for those gathered. The blank stares from your guests will turn into smiles as you tell them not to worry, you have a backup tank. This will make you a hero.
As for the grill itself, you know what you have to do. Clean it! There should be no evidence of grease left on the grate, the burners, or the grease catcher under the burners. I just hose them off in the street. If you want to get fancy, get some rubber gloves and a sponge that you are willing to sacrifice after the cleaning, and scrub it down. This will make a difference for sure. If the grate is too far gone, go buy a new one. The same goes for the burners. You will have a "new look" grill. Your grill will probably be much more efficient.
The accessories that are out there will amaze you. Most people cook burgers or brats and occasionally chicken on their grill. You will be inspired though, at the sight of the extras that are out there to enhance not only the taste of your food but your efficiency in preparing it. Grilling veggies on the grill are made so much easier with the proper tools.
After it's cleaned up, after you have picked up a new accessory and after you have two full tanks to get you through the summer, try cooking something that you are not familiar with. I love to have an experimental run with just family, then when you are ready for a bigger crowd show off and go for the homerun with something unusual. Nothing makes you fell better than grilling great food for others, especially when they are in awe of what you have prepared. Your grilling should always be a sense of pride. It is for me.