Being that I like the looks of the Christmas lights and that I have had 20 years of not being able to set them up, I have already taken the step of setting up the Christmas tree. On it are huge amounts of lights--12 sets of C6 LED bulbs (they come 60 to a set) plus a set of 70 miniature LEDs for the top region. I ran out of C6 bulbs about halfway up the tree (not to worry, I have the other 6 sets on order and they should be arriving today).
There are some things to think about when setting up a holiday tree out of "season". The most obvious is that, if you have a window type air conditioner, you should set it up so it will not block the flow of air from that into the room. Otherwise, the air conditioner will not be able to do its job. This is also a factor if you have forced air heating (it will tend to dry out the tree if you use a cut tree); the cold air returns absolutely must not be blocked or the heater will not work properly. This also applies if you choose to decorate the Christmas tree with patriotic ornaments during the summer, which is perfectly legitimate.
Cut trees should not be used so early in the season. Why? They will dry out rapidly, and all the worse if they were still growing when cut or it is quite hot in your living room. Then they lose their needles and create fire hazards. Watering a cut tree will keep it fresh longer, but I doubt you can keep one fresh much longer than 6 weeks at room temperature. If your living room is like a freezer, you should be able to keep the tree alive all winter. Artificial trees do not dry out. Live trees still in containers should not be decorated with heavy or constraining ornaments while still growing for the season, and I would not recommend any other than LED lights for Norfolk Island pines because of the heat these bulbs throw off.
This is what Good Housekeeping recommends, and I have tried it with success (at least as far as I got before the lights ran out). Take the string of lights and unravel the cord near the first bulb. Secure this by looping it around the base of the branch on the first green (or branchlet) nearest the trunk, and run it straight to the tip of the branch. Secure it by unraveling another light bulb partway and looping it on the tip, and run the string back toward the trunk. Higher intensities can be obtained by going out and back on some or all the greens. That is how they do it at department stores. You will also need about 20 base ornaments and 10 good ornaments per foot of tree height, or about 210 ornaments for a 7 foot tree (keeping in mind that wider trees also need more).
It helps to plan for this in advance. For a 7 foot tree, you are going to need about 12 boxes of lights (assuming 60 to a set) to pull this off. If you are using miniatures, you are going to need between 15 and 20 boxes for a 7-foot tree (assuming 50 to a set). If you want a real showcase, you will need up to 80 boxes (yes, 80) of minis for a 8-foot tree. That will run about 1,600 watts of electricity for the set, so plan accordingly. That is close to the maximum that a 15-amp circuit breaker can handle, so prepare to blow a fuse or two or trip a circuit breaker (LEDs only use 160 watts for the same 4,000 lights and are much easier on your fuses and light bills).
How much time will this take? Likely a couple of hours for a 7-foot tree. Securing the lights on the greens nearest the trunk, running it up and back on the branch, and then running it up the next branch takes the time. If your lights are all tangled up or there are blown bulbs, they will take longer. Damaged cords should never be used, and for minis if you have wires sticking out from the socket in the bulb, they need to be trimmed or you risk electrocution or fire. Use of lights on metal trees, except sealed LED bulbs, is at your own risk because a needle can find its way into a socket.
Finally, if you were raised a Witless and never set up a Christmas tree, be warned that it is going to take a lot more items than you might think to have a good showcase tree. Many people will throw a few lights on a tree and a few ornaments, and then find that it looks wimpy. They might think one or two boxes of lights and a dozen or two ornaments will do, put it all up, and then wonder why it looks skimpy compared to the masterpieces found in catalogs and stores. You will probably need at least 12 boxes of lights (50 to a box) and at least 150 ornaments to make the tree look proper. And, patience is the essence. The earlier you set it up, the more time you will have to fix any deficiencies that are sure to happen because you didn't plan on enough ornaments or you want a particular theme or color schematic.
And, if you are currently a Witless and not faded out or disassociated, you can plan on some visits from Brother Hounder once the tree is lit. If you are serious about celebrating Christmas, you should plan accordingly and expect to be disfellowshipped if you get caught. It helps to cut down on the hounding if you tell them that if they don't leave you alone, that you are going to light it and put on some Christmas music for them to listen to. This might not be an option if you have ties in the organization that you wish to maintain, however.