PBP - Ever-Changing
The one constant is this world is that nothing is constant. This means that as years go by, we have to adapt our practices, especially in reconstructuralist paths.
Sacrifice
Convenience
Centuries ago, if you needed a fire, you created one or carried one back from the communal flame at the town center. This fire could be used to warm your home, cook food, and make sacrifices. Now, we have heating and stoves, but there isn't an easy replacement for the third one. Special precautions have to be made, and the idea of a perpetual household fire no longer exists.
This can easily be overcome with a temporary flame. Getting a fire started at home is not difficult anymore, and modern life doesn't allow someone to stay at home to watch over it 24/7 anymore.
"Basic" offerings like incense or wine are not scarce. In fact, they are cheap. If you need more dragon's blood, you can just jump on Amazon and get some. You don't even have to leave the house.
Modern convenience gives us luxuries that the ancients never had. It's not a "sacrifice" in the same sense of the word. Nevertheless, it's what we do. As an employed man who lives near a metropolis, offering an egg to Hekate is ultimately a $0.25 practice, not a symbol of sacrifice and hardship. I'm grateful for that, and I hope it will always be that way.
On the other hand, I have no excuse not to practice for the same reasons. There is no debate on whether I can share my food vs. going hungry. If I don't practice daily, then I'm saying that I didn't have time for the Gods because I was too busy watching TV; They are second priority to forgettable YouTube clips. The only acceptable reason to forgo practice at home is miasma, and even then it is accompanied by guilt.
Difficulties
How do you dispose of the ashes if you live in a city? Do you create a "sacred garbage" bag to be thrown in the same dumpster later? What about libations?
Cthonic Gods are given offerings by digging a trench and pouring a khoe. What do you do if you live in a city? There is no dirt for miles, and the neighbors won't appreciate me running a jackhammer in the parking lot at midnight for Hades.
Definitions
Then, there are changes in definition to which we have to adapt.
The most obvious term that has changed is the oikos (οικος), meaning the household. Each family had its own household in its own house. Two changes of modern life make this confusing.
What about apartments and condos? Is the building one oikos, or is each unit an oikos? What of mother-daughter houses where all that separates the units is an open staircase? If there is an agathos daimon per household, where does each daimon's boundary lie?
A new oikos isn't formed until a marriage. But, I haven't lived with my parents in nearly 10 years. I've been with my fiancée for six years, and we've lived together for most of our relationship. Are we still considered to be in two separate oikoi, neither of which is our own?
Use Your Judgment
At some point, we have to make a judgment call for our practices. The next generation will think we are wrong about some of it, just as we will think the same of them. In the end, no one knows what is right. It has been thousands of years; chances are that none of us are doing anything "correctly."
The oldest known altar is from 3000 B.C.E. In 4-5 millennia, things have changed, and our practices have had to change with it. It's important to keep tradition, but that doesn't mean that if you can't do it "properly" that you shouldn't do it at all. Find a way to make it happen, even if it's "non-standard."