VTA adjustment for VPI 10.5i tonearm

Do you get best results with the tonearm level with the platter, or with the rear of the arm higher or lower at the pivot? It's difficult to gauge levelness because of the tapered tonearm design. I'm using a Lyra Titan-i cartridge. Thanks!
lyras will benefit at lower at the pivot.
Use the top of the headshell area where the cartridge is mounted, not the arm tube.

I made up a 3 X 5 card with extra lines using a T-square. With the stylus on a stationary record I set the card immediately behind the cartridge and site at eye level along the top of the headshell. This tells me if I'm parallel, up or down.
Thank you both for your suggestions. I'll try sighting along the headshell instead of the armtube.
Regardless of how look at it, it's what you hear that matters.

Making your armtube or cartridge perfectly level is pointless. Marakanetz's advice was useful, being specific to your cartridge, but even the ideal visual indicator (SRA measurement) only gives you a rough starting point. Obsessing over it is a waste of time. Ultimately you must use your ears - unless you bought that Titan-i to look at more than to listen to! ;-)
Absolutely agree Doug, except saying level is pointless. Where do you suggest someone begin for VTA with a cartridge installation?

LISTENING must be the key to the process. So how about beginning with the cartridge adjusted for level, then listening awhile. Now raise the arm a bit at the pivot point and listen again. Measure this position (easy with the scale on the VPI arm and a few others, otherwise find a way to measure the amount of elevation on the arm post). Then lower the arm below the initial level setting and listen yet again. Measure this position. Now the person should have an idea about what sounds best in their set up. If either the positive (higher at pivot) or negative (lower at pivot) VTA sounds clearly better than the other or level, return to that point (this is why you measure) begin fine tuning with small increases and decreases until it is dialed in. Think of it like focusing a telephoto lens, moving back and forth until optimum sharpness (musicality) is achieved.

And further for the OP, realize that different hobbyists take VTA to different degrees. Some may use an average thickness record and set VTA for that. Others may identify (another reason for measuring) settings for say 150, 180, and 200 gram LPs and make a quick adjustment when each type is played. The most obsessive may do listening tests for each of their favorite records and make a note of that particular VTA so they can quickly readjust for that. I assume the later group always have arms with some form of calibrated VTA scale.
Listening is good.

Another question though: What are the margins for the needle's placement in the cantilever? Is it really that exact between different carts of the same model? Or different models? Small margins here would make a lot of difference in VTA/SRA, and the question regarding the tone arm's position, relative to parallell or not to the record, quite uninteresting.
Thanks again for your responses, all useful information. I started experimenting last night, slightly raising and lowering VTA and listening with a friend. I do not obsess over it, just want to maximize the sound quality for best overall sound quality and leave it there. Small changes can make a difference!
From my limited experience I would say don't be afraid to make large adjustments up and/or down from level. A small change of say 1/16 of an inch at the rear of the arm will net almost no adjustment at the stylus. What sounds good to you might be beyond a "small" adjustment, such as moving the rear of the arm 1/4 inch (maybe more). I made the mistake in my system of too small of adjustments for a long time till I moved the arm a large amount and then found what I liked, for now.

Good luck,
I'll try that. I was making pretty small changes, not nearly as much as you suggested. A large adjustment in VTA can affect VTF, so I'm aware that this has to be checked. Thanks for your input!
Most records are cut at a 22 degree VTA. So if you can emulate the angle with the cantilever you are 95% there. I cut a 22 degree angle in a piece of white board bent it at rt. angles so that it would stand up , placed it on a stationary record on the turn-able, lowered the stylus/tonearm onto the record, lined up the cantilever with the 22 degree edge of the card by adjusting the VTA and I had almost hit the hot spot immediately. After that it is minor increments where you let your ear take over.