So for Lent, you're trying to develop your attitude of gratitude? Great. Giving thanks not only gives God His due credit, it helps give us perspective. Make it a point to give thanks daily and experts say you will become more positive.
May I suggest keeping a gratitude diary? Force yourself to write down things you're grateful for. One benefit of a keeping a journal will be when you're down, reviewing it may help lift you back up by reminding you how much God's blest you.
But don't just thank God for things. Thank him for people. Thank God for people He's put in your life; who have been a blessing to you somehow, have taught you things or have meant something to you.
Mentors, examples, inspirations, helpers, just good company. Friends, relatives, coworkers, neighbors, whomever.
Oh, and here's an idea- if you're grateful for them, why not take a minute to pray for them? At least ask God to bless the and their families, even if you have no idea what any of their specific needs are for intercession. Just blessings.
Those blessings will multiply and you'll have even more to be thankful for!