Shavuot is a holiday that is hard to get a hold of.
It's a time of being.
There isn't any commandment associated with this time, it isn't even given a specific day or date. We are told to count from Passover for 49 days and the day after you finish is the time to stop counting.
Shavuot is an atzeret just like Shemini Atzeret after the holiday of Succot.
It was described in a shirur I heard by Rabbinet Chana Juravel on Aishaudio.com that an atzeret is to stop and celebrate our relationship with Hashem. After an entire month of Tishrei, Rosh Hashanna and Yom HaKippurim and finally Succot, Hashem says to the Jews, just stay with Me one more day. Let's just be together, before we go back to the everyday world.
Shavuot is essentially the same: Hashem asks us to come together and just be with Him. We're taught that the Jewish people were on the saem level as Adam HaRishon before the Chet at the giving of the Torah at Sinai. Adam had this is same quality: he could just be there with Hashem. After the Chet he and Hava “hid” from Hashem. They couldn't be in His presessce any more and had to leave the Garden.
So this is a time to return , just like the time of Tishrei, and to attempt to simply be with Hashem.
I once heard a beautiful story from a woman who had a huge nissiyon in shiduchim. She looked for a husband for over 13 years. She said that when she was 15 years old she told her father that she and a couple of friends were going to stay awake all night and read Tehillim(Psalms) and study Chumash with Rashi. Her father told her if she wanted to do something constructive on Shavuot, she should pray for shefa ruchani. The best way to do that was for her to pray for her future husband since he would be her main source of ruchanius in her life. They talked it over and in the end, she read Tehillim with her girlfriends and went to bed on time. But she did pray for her future chatan, her husband. She prayed over and over and even cried a few times. Years later when she was married, just before Shavuot, her husband was talking about how one Shavuot, when he was a teenager, he had such an amazing experience with the studying and prayers that he decided to go to a different yeshiva the following year and that is where he met his rav and it changed his whole life. He told her that that one day made all the difference in the direction of his life and he never would have met her if it weren't for the changes he made because of it. It turned out to be that same Shavuot that she prayed and cried.
What are you expecting on Shavuot?
What outpouring of abundance do you need or want in your life?
How can you be with Hashem this holiday? How can you just bask in His Presence?
It doesn't have to be long-make a list. The heavens are open. Share yourself with Your Avinu sh'b'shamim.