The highly-rated midfielder sealed a switch to White Hart Lane in January, requiring him to find his feet quickly in new surroundings.
With little time offered in which to adjust to life in a new country, a new city and a new division, Holtby admits he needed a break over the summer to properly acclimatise.
He claims to have now done just that and is confident that he and Spurs - regardless of the summer departure of Gareth Bale to Real Madrid - are ready to kick-on.
Holtby told the Evening Standard: "It's always difficult to join a club in January, especially when there are not many other signings, and I needed a little bit of a break and a pre-season just to get to know everyone better.
"I feel very welcome now. I feel at home here in the team, so now I can show what I'm really capable of, and I think I'm progressing.
"Do we have a more balanced squad now? Definitely. Respect to Gareth who was awesome here, a fantastic guy and a fantastic player, but the new players have really adapted to our team and our style of football.
"The Premier League is very tight and it will be very close at the top. You see how much money all the clubs are spending, like Cardiff, who were promoted only last season.
"But we are fourth now and if we can continue to adapt to each other, then we have big objectives to aim for."
Meanwhile, Holtby expects the growing number of Germany internationals plying their trade in the Premier League to continue rising, with scouts flocking to the Bundesliga to cast an eye over top talents.
He added: "(Julian) Draxler is on the list of every big team. He is a fantastic young player and I think a lot of money will probably be spent on him. I don't know whether he wants to come but there are a lot of players there.
"People say Marco Reus is in talks with everyone here so Germany have a number of big talents and the Premier League is very keen on getting them in. You also look at Adam Szalai, the Hungarian striker at Schalke.
"It's good that so many Germans are coming to the Premier League, which I believe is the best and most attractive competition in the world. German players are very dedicated and professional. It's the dedication that makes them attractive to clubs."