One of the things that we have lost in modern times is the proper habit of caring for our clergy. Indeed, we often hear appeals from our clergy for this or that project when the reality is that it should be us proactively asking them what they need. They are God's, and so when we give to the clergy we are simply rendering to Him what is lawfully and rightfully His.
Whether you live near your clergy or visit only occasionally, find out what the food situation is. Don't assume that "someone else" has it handled. It isn't always a hot meal that is needed: sometimes the pantry needs to be stocked or fresh fruits brought.
While our traditional clergy often buy quality cassocks that last a long time, they do need to buy shirts and trousers that are worn underneath, and these do wear out. Ask Father how he is sorted for clothing and/or vestments. The latter are more costly, but if a new set is needed, you can get a few friends together to deal with different parts. One person buys the stole, another the maniple, and so on. Before you know it, you have a complete set paid for.
Many of us do not have the ability to perhaps cover all the living costs of the clergy, but why not the water, or electricity, internet, or gas bill? Most utility companies can easily send a bill to a different address - why not give them yours? What about repairs? Are there repairs that can be done over a weekend (or several) that you can contribute labor or materials to?
European clergy can often get by on public transportation but US, Australian, and African clergy need personal vehicles. Ask Father if he needs money for gas or for oil changes. As with the house repairs, ask if there are car repairs you can help with. You can also provide transportation to the airport so that they don't have to pay for parking. That gives them time to say their Office while you drive and/or you can utilize some precious private time to ask questions or seek counsel/direction.
Food, clothing, shelter, and transportation are the bare minimum that the clergy need in order to service us and provide for their own support. Whenever priests provide a service you should be in the habit of handing them some kind of compensation, be it money, food, etc. This is not because the sacraments "cost" but because the laborer is worthy of his hire. Did Father bless some things for you? Did he take some time to counsel you on a problem? Grace your home for a meal? Enthrone the Sacred Heart? Make it a normal habit to always be giving Father something, or asking what he needs.
This is to say nothing of Mass stipends, perhaps the most valuable investment you can make while alive. Have Masses offered for the faithful departed, for your own conversion, for your enemies, for all who have claim on your prayers. In all my travels I find that very rarely are clergy "all booked up" when it comes to Mass stipends. You will surely regret these missed "investment opportunities" on your deathbed, especially if your spare change went for the little nothings of this world instead.
Ask Father what his medium and short term projects and plans are. Ask what the long term projects are. Be involved, don't wait for him to ask, and most importantly, don't think that "someone else has it handled." That "someone else" is you.
Remember Our Lord sitting outside the Temple watching people throw money into the collection and calling attention to the widow's mite. Our Lord notes that she gave not out of her abundance, but out of her necessity. Is it not certain that Our Lord matched or exceeded her generosity? Do we dare to see if Our Lord will be faithful to us? Or have our hearts grown too cold to even try?
There's no better time in this season, in the fleeting moments before Our Lord ascends to the Father, while the bridegroom is still with us, to find out.