Some of us will be able to find Bilvapatra leaves please offer them to shivji/shivlingam.
Last year I was in India at this time and was able to do the same. Sadly this year, I am in NJ and cannot find Pilvaparta. However, we will have a wonderful Milk abhishek /maha abhishek to Lord Shiv at our local temples.
Anyone who is not able to visit temples, can/ should most definitely pray at their respective homes and get blessing from the creator of the universe.
You can perform the abhishek by slowly offering milk in a thin stream (with a nozzle pot or a small cup that can create a steady small stream on top of the shiv lingam while chanting ॐ नमः शिवायः Om Namah Shivay for 5,7,9,11, or 21 or 108 times is the simplest form of abhishek one can perform. After which you can end it by flowers and rice and chandan tilak. This would be a short simple puja. Bilva patra (three petaled leaf) is very dear to lord shiva and you offer that as well if you are able to find it in your area. Flowers would do as well, inc ase the bilvapatra is not available. Conclude with aarti at the end if you have time.
Best times for this puja would be early in the morning after shower. For those with busy schedules, any time that is peaceful and quiet and suits your daily schedule is good. Just before midnight, around sunset are other preferred best times for this puja. Most important is you should have the inner will and intention to do the puja. I am posting below all the shiv puja links from my blog on one page.
Om Namah Shivay ॐ नमः शिवायः simple short mantra for Lord shiva (narrate 108 times if possible) while doing abhishek.
Shiv Manas Pooja श्री शिव मानस पूजा (under seven minutes) as well during abhishek.
Dwaadash Jyotirlingaani द्वादश्ज्योतिर्लिङ्गानि (written sanskrit/english) twelve names of Lord Siva jyotirlingam. under two minutes
Vedasaar shivastavah वेदसारशिवस्तव (under six minutes) shiv prayers